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Dr. Kennedy's Vocabulary Course: -C-
(View Course for 11/18/2013)
(A B C D E F G H I J K L M)
 
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Ron Kennedy, M.D.
 
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- C -
(A B C D E F G H I J K L M)
-cidal:  Suffix indicating killing, as in bacteriocidal (capable of killing bacteria) and in suicidal (the killing of oneself).
-cide:  Suffix indicating killing or killer, as in bactericide (a solution capable of killing bacteria).
Campylobacter jejuni:  A bacterium that typically infects the bowels. Now the leading cause of bacterial food poisoning, Campylobacter jejuni is most often spread by contact with raw or undercooked poultry. A single drop of juice from a contaminated chicken is enough to make someone sick. Disease caused by Campylobacter jejuni is termed Campylobacteriosis. Campylobacteriosis usually strikes only one person or a few people at a time. A common way to become infected is to cut poultry meat on a cutting board, and then use the unwashed cutting board or utensil to prepare vegetables or other raw or lightly cooked foods. The Campylobacter organisms from the raw meat can then spread to the other foods. The organism is not usually spread from person to person, but this can happen if the infected person is a small child or is producing a large volume of diarrhea. Many chicken flocks are silently infected with Campylobacter; that is, the chickens are infected with the organism but show no signs of illness. When an infected bird is slaughtered, Campylobacter can be transferred from the intestines to the meat. More than half of the raw chicken in the US market has Campylobacter on it. Campylobacter is also present in the giblets, especially the liver.
Chlamydia trachomatis:  A bacterium that causes a disease called trachoma that results in blindness so frequently that it places a huge burden a year on world health funding ($25 billion in the year 2000). The disease goes by a number of names such as sandy blight. The transmission of Chlamydia trachomatis is mainly among children and from children to women during child care. Key risk factors include low socioeconomic status and inadequate supplies of water. Trachoma affects approximately 500 million people worldwide, primarily in rural communities of the developing world and in the arid areas of tropical and subtropical zones. About 6-9 million people worldwide are currently blind and many more have suffered partial loss of vision from trachoma. Australia is the only developed country where trachoma is still a significant health problem; there it affects an estimated 100,000 people. The mass treatment of trachoma with tetracycline ointment is effective in the short term, but the disease usually returns within 6-12 months to pretreatment levels in a community. Trachoma can now also be treated with the antibiotic azithromycin (brand name: Zithromax). Promotion of increased face-washing helps further to control the disease. Surgery of the scarred eyelids can prevent continued damage to the cornea by turned-in lashes.
Chlamydia:  A type of bacteria one species of which causes an infection very similar to gonorrhea in the way that it is spread, the symptoms it produces, and the long-term consequences.
Clostridium botulinum:  A group of rod-shaped bacteria commonly found in the soil that grow best under low oxygen conditions. The bacteria form heat-resistant spores which allow them to survive in a dormant state until exposed to conditions that can support their growth. Clostridium botulinum produces botulinum toxin, a highly potent neurotoxin and the basis of the disease botulism. Clostridium botulinum and its spores are widely distributed in nature. They occur in both cultivated and forest soils, bottom sediments of streams, lakes, and coastal waters, and in the intestinal tracts of fish and mammals, and in the gills and viscera of crabs and other shellfish.
Clostridium difficile:  A bacterium that is one of the most common causes of infection of the large bowel (colon). In technical terms, Clostridium difficile (C. difficile) is an obligate anaerobic or microaerophilic, gram-positive, spore-forming, rod-shaped bacillus. C. difficile is now recognized as the chief cause of nosocomial (hospital-acquired) diarrhea in the US and Europe. Patients taking antibiotics are at risk of becoming infected with C. difficile. Antibiotics disrupt the normal bacteria of the bowel, allowing C. difficile bacteria to become established in the colon. The chief risk factor for the disease is prior exposure to antibiotics. A prolonged course of antibiotics or the use of two or more antibiotics in combination increases the risk of C. difficile diarrhea. The cephalosporin antibiotics are the leading instigators of C. difficile diarrhea. Other culprits include clindamycin, ampicillin, and amoxicillin. Many persons infected with C. difficile bacteria have no symptoms. These people become carriers of the bacteria and can infect others. In other people, a toxin produced by C. difficile causes diarrhea, abdominal pain, severe inflammation of the colon (colitis), fever, an elevated white blood count, vomiting and dehydration. In severely affected patients, the inner lining of the colon becomes severely inflamed (a condition called pseudomembranous colitis). The walls of the colon can wear away and holes can perforate the colon, leading to a life-threatening infection of the abdomen.
Clostridium perfringens:  A type of bacteria that is the most common agent of gas gangrene and can also cause food poisoning as well as a fulminant form of bowel disease called necrotizing colitis. Clostridium perfringens is the same as Clostridium welchii.
C-peptide:  A byproduct of insulin production, usually by the pancreas. The level of C-peptide is a gauge of how much insulin is being produced in the body. C-peptide is made up of chemical compounds called amino acids. When the pancreas produces insulin, it releases C-peptide into the bloodstream at the same time. The amount of C-peptide in the blood can indicate the presence or absence of disease. For example, abnormally low amounts of C-peptide in the blood suggest the insulin production is too low (or absent) because of type I diabetes, also known as juvenile or insulin dependent diabetes. Abnormally high amounts of C-peptide warn of the possible presence of a tumor called an insulinoma that secretes insulin. Normal levels of C-peptide may signal that all is well. However, in a person with diabetes, a normal level of C-peptide indicates the body is making plenty of insulin but the body is just not responding properly to it. This is the hallmark of type 2 diabetes (adult onset insulin-resistant diabetes). This slides into the metabolic syndrome (aka syndrome-X) when the pancreas produces too much insulin producing a state of insulin toxicity.
C-reactive protein:  A plasma protein that rises in the blood with the inflammation from certain conditions. C-reactive protein (CRP) is one of the plasma proteins known as acute- phase proteins: proteins whose plasma concentrations increase (or decrease) by 25% or more during inflammatory disorders. CRP can rise as high as 1000-fold with inflammation. Conditions that commonly lead to marked changes in CRP include infection, trauma, surgery, burns, inflammatory conditions, and advanced cancer. Moderate changes occur after strenuous exercise, heatstroke, and childbirth. Small changes occur after psychological stress and in several psychiatric illnesses. CRP is therefore a test of value in medicine, reflecting the presence and intensity of inflammation, although an elevation in C-reactive protein is not the telltale diagnostic sign of any one condition. Since inflammation is believed to play a major role in the development of coronary artery disease, markers of inflammation have been tested in respect to heart health. CRP was found to be the only marker of inflammation that independently predicts the risk of a heart attack. (N Engl J Med 2000;342:836-43.)
C-section:  Short for Caesarian section, a procedure in which a baby, rather than being born vaginally, is surgically extracted (removed) from the uterus. As the name "Caesarian" suggests, this is not exactly a new procedure. It was done in ancient civilizations upon the death of a pregnant woman who was near full term in order to salvage the baby. Julius Caesar (or one of his predecessors) was born by this procedure. Hence, the name "Caesarian." The term "section" in surgery refers to the division of tissue. What is being divided here is the abdominal wall of the mother as well as the wall of the uterus in order to extract the baby.
CA 125:  A cancer marker, a protein normally made by certain cells in the body including those of the uterine tubes, uterus, cervix, and the lining of the chest and abdominal cavities (the peritoneum and pleura). CA 125 stands for cancer antigen 125. CA 125 is measured in a blood sample or fluid from the chest or abdominal cavity.
CABG:  Acronym for Coronary Artery Bypass Graft (see below). Pronounced "cabbage." An overused expensive (lucrative) procedure usually done without explaining alternatives to the patient and without informing the patient that large scale study has not documented improvement in mortality with CABG versus conservative medical management.
CABG, Off-pump:  A coronary artery bypass graft (CABG) done without putting the patient on a heart-lung machine. Off-pump CABG permits surgery on multiple vessels within the heart by mechanically stabilizing it. Off-pump surgery is minimally invasive, as compared to surgery on the heart-lung machine. The potential benefits include shorter hospital stay, less bleeding, less chance for infection, less risk of irregular heartbeats (arrhythmia), less trauma, shorter recovery time, and greater cost effectiveness. Off-pump CABG was initially created to avoid brain injuries attributed to the pump. However, no differences have been found in the rate or extent of mental decline in people who had traditional on-pump surgery as compared to those who had off-pump CABG. The rate of grafts that are still patent (open) 3 months after surgery was found to be lower with off-pump surgery than with on-pump surgery (88% vs. 98%), according to a 2004 study. The lower graft-patency rate with off-pump surgery is a risk of off-pump CABG.
Cachexia:  Physical wasting with loss of weight and muscle mass caused by disease. Patients with cancer, AIDS, or other major chronic diseases may appear cachetic.
CAD:  Acronym for Coronary Artery Disease. CAD is a major cause of illness and death. It begins when plaques form within a coronary artery. These coronary arteries arise from the aorta adjacent to the heart and supply the heart muscle with blood that is rich in oxygen. They are called the coronary arteries because they encircle the heart in the manner of a crown (corona). The plaques in the coronary arteries can cause a tiny clot to form which can obstruct the flow of blood to the heart muscle producing symptoms and signs of CAD that may include: 1. Chest pain (angina pectoris) from inadequate blood flow to the heart; 2. Heart attack (acute myocardial infarction), from the sudden total blockage of a coronary artery; or 3. Sudden death, due to a fatal disturbance of the heart rhythm.
CADASIL:  Acronym for Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. An inherited form of vascular dementia that strikes relatively young adults of both sexes and is characterized by multiple strokes, dementia, migraine-like headaches, and psychiatric disturbances. CADASIL is due to mutation of a gene called NOTCH3 located on chromosome 19. Also called hereditary multi-infarct dementia.
Cadaver:  A dead human body that may be used by physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Students in medical schools study and dissect cadavers as part of their education. The word is derived from the Latin word cadere (to fall).
Cadaver wart:  A warty growth on the hand due to tuberculosis, typically of someone doing postmortem examinations. A cadaver with unsuspected tuberculosis was once a major hazard for pathologists and others in the autopsy room. Cadaver warts were among the least of the dangers.
Cadmium:  A metallic element whose salts are toxic and cause cancer. Cadmium and cadmium compounds were upgraded in 2000 by the U.S. government to the status of "known human carcinogens." These materials are used in batteries, coating and plating, plastic and synthetic products and alloys, and have been found to carry an increased risk of lung cancers in workers exposed to cadmium and cadmium compounds.
Caduceus:  A rod with two snakes entwined about it topped by a pair of wings. The caduceus served as the symbol of Hermes and Mercury, the Greek and Roman messenger gods. The caduceus was the sign of a herald and hence a logical symbol for the messenger. Because of a misconception, the caduceus became the insignia of the U.S. Army Medical Corps. The Medical Corps should have chosen the symbol of medicine, which is the rod of Aesculapius, which has only one snake and no wings atop it. No wings were necessary since the essence of medicine is not speed. The single serpent that could shed its skin and emerge in full vigor represents the renewal of youth and health - medicine.
Caecum:  The caecum (also spelled cecum), the first portion of the large bowel, situated in the lower right quadrant of the abdomen. The caecum receives fecal material from the small bowel (ileum) which opens into it. The appendix is attached to the caecum. The word "caecum" comes from the Latin "caecus" meaning "blind." This refers to the fact that the bottom of the caecum is a blind pouch (a cul de sac) leading nowhere.
Caesarian section:  Also referred to as a C-section (see above). A procedure in which a baby, rather than being born vaginally, is surgically extracted (removed) from the uterus. As the name "Caesarian" suggests, this is not exactly a new procedure. It was done in ancient civilizations upon the death of a pregnant woman who was near full term in order to salvage the baby. Julius Caesar (or one of his predecessors) was born by this procedure. Hence, the name "Caesarian."
Café au lait spot:  A flat spot on the skin that is the color of coffee with milk (café au lait) in persons with light skin, or a darker appearance (café noir) than the surrounding skin in persons with dark skin. About 10% of the general population have café au lait spots, and they can be removed with a Yag laser. Café au lait spots are in themselves harmless, but in some cases they may be a sign of neurofibromatosis. The presence of 6 or more café au lait spots each of which is 1.5 centimeters or more in diameter is diagnostic of neurofibromatosis. Conversely, most people with neurofibromatosis who are at least 5 years old have 6 or more café au lait spots 1.5 centimeters or more in diameter.
Caffeine:  A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea. Caffeine is an alkaloid. It is metabolized in the liver and the breakdown products of caffeine are excreted through the kidney. In women on oral contraceptives, the rate at which they clear caffeine from the body is considerably slower. Pregnancy reduces a woman's ability to process caffeine still further. The half life of caffeine in an adult is about 3 to 4 hours. In pregnancy, it is 18 hours. In doses of 100-200 mg. caffeine can increase alertness, relieve drowsiness and improve thinking. At doses of 250-700 mg/day, caffeine can cause anxiety, insomnia, nervousness, hypertension, and insomnia. Caffeine is a diuretic and increases urination. It can curiously enough make it more difficult to lose weight because it stimulates insulin secretion, which reduces serum glucose, which increases hunger. Caffeine can help relieve some headaches, so a number of over-the-counter and prescription pain relievers include it as an ingredient, usually with aspirin or another analgesic.
Calamine:  An astringent made from zinc carbonate or zinc oxide, usually used in lotion form to treat skin problems that cause itching or discomfort.
Calcaneal spur:  A bony spur projecting from the back or underside of the heel bone (the calcaneus) that often makes walking painful. A calcaneal spur is also called a heel spur. Spurs at the back of the heel are associated with inflammation of the Achilles tendon (Achilles tendinitis) and cause tenderness and pain at the back of the heel that is made worse by pushing off the ball of the foot. Spurs under the sole (plantar area) are associated with inflammation of the plantar fascia (the "bowstring-like" tissue stretching from the heel underneath the sole) and cause localized tenderness and pain made worse by stepping down on the heel. Not all heel spurs cause symptoms. Some are discovered on X-rays taken for other purposes. Heel spurs and plantar fasciitis can occur alone or be related to underlying diseases which cause arthritis (inflammation of the joints) such as Reiter's disease, ankylosing spondylitis, and diffuse idiopathic skeletal hyperostosis.
Calcaneus:  The calcaneus is the heel bone. It is also called the os calcis. The calcaneus is a more or less rectangular bone at the back of the foot. The word "calcaneus" comes from the Latin calx meaning limestone. The heel bone looked like a lump of chalk (to someone). The word "calcium" also comes from calx.
Calcific bursitis:  A bursa is a thin fluid-filled sac that reduces friction forces between tissues of the body. Chronic (repeated or long-standing) inflammation of the bursa (bursitis) can lead to calcification of the bursa. The calcium deposition (calcification) can occur as long as the inflammation is present.
Calcification:  The process of building bone by suffusing tissues with calcium salts. Also called ossification.
Calcified granuloma:  A calcified granuloma is a granuloma containing calcium deposits. Since it usually takes some time for calcium to be deposited in a granuloma, it is generally assumed that a calcified granuloma is an old granuloma. A granuloma is one of a number of forms of localized nodular inflammation found in tissues. The fact that a granuloma is localized is important. So is its nodularity. Granulomas have a typical pattern when examined under a microscope. Granulomas can be caused by a variety of biologic, chemical and physical irritants of tissue. For example, a calcified granuloma in the lung may be due to tuberculosis contracted years earlier that is now dormant.
Calcimimetic:  A drug in a class of orally active, small molecules that decrease the secretion of parathyroid hormone (PTH) by activating calcium receptors. The secretion of PTH is normally regulated by the calcium-sensing receptor. Calcimimetic agents increase the sensitivity of this receptor to calcium, which inhibits the release of parathyroid hormone and lowers parathyroid hormone levels within a few hours. Calcimetics are used to treat hyperparathyroidism, a condition characterized by the over-secretion of PTH that results when calcium receptors on parathyroid glands fail to respond properly to calcium in the bloodstream. In March, 2004 the US Food and Drug Administration (FDA) approved the drug cinacalcet (Sensipar), the first calcimimetic, to treat to treat secondary hyperparathyroidism in patients with chronic kidney disease on dialysis, and hypercalcemia in patients with parathyroid cancer. Elevated levels of PTH, the hallmark of secondary hyperparathyroidism, are associated with altered metabolism of calcium and phosphorus, bone pain, fractures, and an increased risk for cardiovascular death. Treatment with cinacalcet lowers serum levels of PTH as well as the calcium x phosphorus ion product. The calcium x phosphorus ion product is a measure of the amount of calcium and phosphorus in the blood, and when elevated, causes harmful deposition of calcium in various parts of the body. Hypercalcemia is associated with parathyroid carcinoma, a rare cancer that causes significant elevations in serum calcium levels. Elevated levels of serum calcium can cause mental confusion, lethargy, dehydration, nausea, vomiting, constipation, and kidney damage.
Calcinosis:  An abnormal deposit of calcium salts in body tissues, as is seen in some forms of disease.
Calcipotriene:  A synthetic form of vitamin D3 that can be applied to the skin to treat psoriasis - not any better than D3 itself, and more expensive.
Calcitonin:  A hormone produced by the thyroid gland that lowers the levels of calcium and phosphate in the blood and promotes the formation of bone. Calcitonin is given in hypercalcemia (high blood calcium) to lower the calcium level; in osteoporosis to increases bone density and decrease the risk of a fracture; and in Paget disease to decrease bone turnover and bone pain. Calcitonin is also called thyrocalcitonin.
Calcitriol:  The active form of vitamin D. Calcitriol is formed in the kidneys or made in the laboratory. It is used as a drug to increase calcium levels in the body in order to treat skeletal and tissue-related calcium deficiencies caused by kidney or thyroid disorders.
Calcium:  A mineral found mainly in the hard part of bones, where it is stored. Calcium is added to bones by cells called osteoblasts and is removed from bones by cells called osteoclasts. Calcium is essential for healthy bones. It is also important for muscle contraction, heart action, nervous system maintenance, and normal blood clotting. Food sources of calcium include dairy foods, some leafy green vegetables such as broccoli and collards, canned salmon, clams, oysters, calcium-fortified foods, and tofu.
Calcium channel blocker:  A drug that blocks the entry of calcium into the muscle cells of the heart and the arteries. It is the entry of calcium into these cells that causes the heart to contract and arteries to narrow. By blocking the entry of calcium, calcium channel blocker (CCBs) decrease the contraction of the heart and dilate (widen) the arteries. By dilating the arteries, CCBs reduce the pressure in the arteries. This makes it easier for the heart to pump blood, and, as a result, the heart needs less oxygen. By reducing the heart's need for oxygen, CCBs prevent or relieve angina. CCBs also are used for treating high blood pressure because of their blood pressure-lowering effects. CCBs also slow the rate at which the heart beats and are therefore used for treating certain abnormal heart rhythms such as atrial fibrillation. The most common side effects of CCBs are constipation, nausea, headache, rash, edema (swelling of the legs with fluid), low blood pressure, drowsiness, and dizziness.
Calcium deficiency:  A low level of calcium in the blood (hypocalcemia) which can make the nervous system highly irritable causing tetany (spasms of the hands and feet, muscle cramps, abdominal cramps, and overly active reflexes). Chronic calcium deficiency contributes to poor mineralization of bones, soft bones (osteomalacia) and osteoporosis and, in children, rickets and impaired growth.
Calcium excess:  Overly high intake of calcium that can result in elevated levels of calcium in the blood (hypercalcemia). This can cause muscle weakness and constipation, affect the conduction of electrical impulses in the heart (heart block), lead to calcium stones in the urinary tract (nephrocalcinosis), impair kidney function, and interfere with the absorption of iron, predisposing to iron deficiency.
Calculus:  1. A stone within the body, such as a stone in the urinary tract. 2. The calcium salt deposits on the teeth. 3. A field of mathematics. These different meanings of calculus all go bach to the origin of the word. In Latin, a calculus is "a pebble." Pebbles were once used for counting, from which came the mathematical field of calculus. A urinary calculus is literally a tiny pebble in the urinary system. And the calculus on the teeth is a pebble in the teeth.
Calipers:  A metal or plastic tool similar to a compass used to measure the diameter of an object. The skin fold thickness in several parts of the body can be measured with skin calipers to estimate lean body mass.
Callus:  The word "callus" has several meanings: (1) A callus or callosity is a localized firm thickening of the upper layer of skin as a result of repetitive friction. A callus on the skin of the foot becomes thick and hard from rubbing (as a result of repetitive friction). (2) A callus is also the word applied to hard new bone substance that forms in an area of bone fracture. It is part of the bone repair process.
Calor:  Heat, one of the four classic signs of inflammation, together with dolor (pain), rubor (redness) and tumor (swelling). From the Latin calor, heat.
Calorie:  A unit of food energy. In nutrition terms, the word calorie is used instead of the more precise scientific term kilocalorie which represents the amount of energy required to raise the temperature of a liter of water one degree centigrade at sea level. The common usage of the word calorie of food energy is understood to refer to a kilocalorie and actually represents, therefore, 1000 true calories of energy. The technical definition of "calorie" is A calorie is the amount of energy required to raise the temperature of one cc (cubic centimeter) of water (by definition one gram) one degree centigrade at sea level; also known as cal, gram calorie, or small calorie.
Canavan disease:  A severe progressive inherited (genetic) disorder of the central nervous system (CNS). The signs of Canavan disease usually appear when the children are between 3 and 6 months of age. They include developmental delay (significant motor slowness), enlargement of the head (macrocephaly), loss of muscle tone (hypotonia), poor head control, and severe feeding problems. As the disease progresses, convulsions (seizures), shrinkage of the nerve to the eye (optic atrophy) and often blondness, heartburn (gastrointestinal reflux) and deterioration of swallowing develop. Most children with Canavan disease die in the first decade of life. There is currently no cure or effective treatment for Canavan disease. Canavan disease is caused by a deficiency of the enzyme aspartoacyclase.
Cancer:  An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread). Cancer is not one disease. It is a group of more than 100 different and distinctive diseases. Cancer can involve any tissue of the body and have many different forms in each body area. Most cancers are named for the type of cell or organ in which they start. If a cancer spreads (metastasizes), the new tumor bears the same name as the original (primary) tumor. The frequency of a particular cancer may depend on age, gender, and sometimes ethnicity. While skin cancer is the most common type of malignancy for both men and women, the second most common type in men is prostate cancer and in women, breast cancer. Cancer frequency does not equate to cancer mortality. Skin cancers are often curable. Lung cancer is the leading cause of death from cancer for both men and women in the United States today. Skin cancer is the most common type of cancer for both men and women. The second most common cancer in men is prostate cancer, in women it is breast cancer. Lung cancer is the leading cause of death from cancer for both men and women in the U.S.
Cancer causes:  In most individual cases of cancer, the exact cause of cancer is unknown. The causes may include increased genetic susceptibility; environmental insults, such as chemical exposure or smoking cigarettes; lifestyle factors, including diet; damage caused by infectious disease; and many more. Although they are not causes per se, many characteristics can influence the development of cancer. These include gender, race, age, and the health of the patient's immune system. The link between overexposure to the sun and skin cancer is well-known, and individuals can easily reduce their risk by avoiding suntanning and sunburns. Smoking is an equally preventable predisposing factor which can be eliminated. Common commercial hair dyes are highly suspect in the provocation of many cancers including lymphoma and skin cancer.
Cancer cluster:  A greater-than-expected number of cancer cases that occurs within a group of people in a geographic area over a period of time. When a cluster is identified an investigation may show the common provoking factor and this information can be used to help prevent similar outbreaks.
Cancer detection:  Methods used to find cancer in persons who may or may not have symptoms. Symptoms of cancer are abnormal sensations or conditions that persons can notice that are a result of the cancer. It is important to your doctor for regular checkups and not wait for problems to occur. But you should also know that the following symptoms may be associated with cancer: changes in bowel or bladder habits, a sore that does not heal, unusual bleeding or discharge, thickening or lump in the breast or any other part of the body, indigestion or difficulty swallowing, obvious change in a wart or mole, or nagging cough or hoarseness. These symptoms are not always a sign of cancer. They can also be caused by less serious conditions.
Cancer, adult primary liver:  A tumor in which the cancer starts during adulthood in cells in the liver. Also called hepatocellular carcinoma. Primary liver cancer is different from cancer that has metastasized (spread) from another place in the body to the liver. The signs and symptoms may include a hard lump just below the rib cage on the right side (from swelling of the liver), discomfort in the upper abdomen on the right side, pain around the right shoulder blade, or yellowing of the skin (jaundice). There is often an increase in the blood levels of alpha-fetoprotein (AFP) and alkaline phosphatase. A rapid deterioration of liver function may be the only clue to the presence of the tumor. Hepatocellular carcinoma is potentially curable by surgery, but surgery is the treatment of choice for only a small fraction of patients who have localized disease. Laparoscopy may detect metastatic disease, tumor in both lobes of the liver, or an inadequate liver remnant, and avoid the need for open surgery to explore the liver. Therapy other than surgery is best as part of a clinical trial. Such trials evaluate the efficacy of systemic or infusional chemotherapy, hepatic artery ligation or embolization, percutaneous ethanol (alcohol) injection, radiofrequency ablation, cryotherapy (freezing the tumor), and radiolabeled antibodies, often in conjunction with surgical resection (removal) and/or radiation therapy. The prognosis (outlook) depends on the degree of local tumor replacement and the extent of liver function impairment. Primary liver cancer (hepatocellular carcinoma) is the most common cancer in some parts of the world. It is still relatively uncommon in the US but its incidence is rising, principally in relation to the spread of hepatitis B and hepatitis C. People who have a disease of the liver called cirrhosis are also more likely to get adult primary liver cancer. Hepatitis B and C appear to be the most significant causes of hepatocellular carcinoma worldwide. People who have both hepatitis B and hepatitis C may be at a higher risk if they consume more than 3 oz. (80 grams) of alcohol a day. A first-degree relative with hepatocellular carcinoma also increases the risk. Hepatocellular carcinoma is associated with cirrhosis in 50% to 80% of patients; 5% of cirrhotic patients eventually develop hepatocellular cancer. Aflatoxin has also been implicated as a factor in the etiology (causation) of primary liver cancer in parts of the world where this mycotoxin occurs in high levels in food. Workers exposed to vinyl chloride before controls on vinyl chloride dust were instituted developed sarcomas in the liver, most commonly angiosarcomas.
Cancer, appendix:  A malignancy of the appendix, accounting for about 1 in 200 of all gastrointestinal malignancies. Although unusual, cancer of the appendix can range in type. The most common type of appendiceal cancer is carcinoid tumor with adenocarcinoma next. Tumors of the appendix often present with peritoneal seeding of the malignant cells. Advances in treatment have raised survival rates to about 80%.
Cancer, basal cell:  The most common type of skin cancer, a disease in which the cancer cells resemble the basal cells of the epidermis, the outer layer of the skin. Basal cell carcinomas usually appear as the classic "sore that doesn't heal." A bleeding or scabbing sore that seems to get somewhat better, then recurs and starts to bleed, may be a basal cell carcinoma. Most basal cell carcinomas are on the face and neck where the skin is exposed to sunlight. However, a fair number show up on parts of the body such as the abdomen, leg, and scalp exposed to little or no sunlight. Basal cell carcinomas typically are locally invasive. They tend to burrow in locally and not metastasize to distant locations. Small basal cell carcinomas can be removed by being burned and/or scraped (electrodesiccation and curettage). Larger basal cells can be removed by surgical resection. Basal cell carcinomas on the scalp, ears, and sides of the nose, as well as those which have come back after being treated, are treated best by Mohs' surgery. One basal cell carcinoma means an increased risk of developing another. Prudent sun precautions and annual skin checkups by the doctor are advisable.
Cancer, bile duct:  An uncommon type of cancer that arises from the bile duct, the tube that connects the liver and the gallbladder to the small intestine. The symptoms of bile duct cancer include yellowing of the skin (jaundice), pain in the abdomen, fever, and itching.
Cancer, bladder:  The most common warning sign of cancer in the bladder is blood in the urine, but there are other causes of blood in the urine. Under any cirucumstances, a finding of blood in the urine must be explained and the cause addressed.
Cancer, bone:  Primary bone cancer, one that begins in bone, is uncommon but it is not unusual for a malignancy to spread to bone from other parts of the body such as from breast, lung, and prostate. The most common type of primary bone cancer is osteosarcoma, which develops in new tissue in growing bones. Another type of cancer, chondrosarcoma, arises in cartilage. Ewing's sarcoma, still another form of bone cancer, begins in immature nerve tissue in bone marrow. Osteosarcoma and Ewing's sarcoma tend to occur in children and adolescents, while chondrosarcoma occurs more often in adults.
Cancer, brain:  Tumors in the brain can be malignant or benign, and can occur at any age. Both are life threatening since they occur in a space enclosed by a rigid boundary (the skull) which does not allow for an expanding space occupying growth without compression damage to brain tissue.
Cancer, breast:  Breast cancer is suspected with self- and physician- examination of the breasts, mammography, ultrasound testing, and is confirmed with biopsy. There are many types of breast cancer that differ in their capability of spreading to other body tissues (metastasis). All women are advised to perform regular self- examinations of their breast tissue to familiarize themselves with the normal lumps and structures. Early detection increases the chance of treatment success. Treatment of breast cancer depends on the type and location of the breast cancer, as well as the age and health of the patient. It may include surgery to remove cancerous tissue only, partial or full mastectomy (removal of the entire breast, and sometimes of surrounding lymph or muscle tissue), or treatment with radiation therapy, chemotherapy, or drugs. A number of factors have been identified that increase the risk of breast cancer. One of the strongest of these risk factors is the history of breast cancer in a relative. About 15-20% of women with breast cancer have such a family history of the disease, clearly reflecting the participation of inherited (genetic) components in the development of some breast cancers. Dominant breast cancer susceptibility genes, including BRCA1 and BRCA2, appear responsible for about 5% of all breast cancer.
Cancer, cervical:  Cancer of the entrance to the uterus. The cervix is the lower, narrow part of the uterus. The uterus, a hollow, pear-shaped organ, is located in a woman's lower abdomen, between the bladder and the rectum. The cervix forms a canal that opens into the vagina, which leads to the outside of the body.
Cancer, colon:  A malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colon polyps. Removal of these precancerous polyps can prevent colon cancer. Colon polyps and early colon cancers cause no signs or symptoms. Full-blown colon cancer can cause occult (a microscopic amount of) blood in the stool, overt rectal bleeding, bowel obstruction, and weight loss. Risk factors for colon cancer include a family history of it or of colonic polyps, and long standing ulcerative colitis. The overall risk can be reduced by following a diet low in fat and high in fiber. Colon cancer is preventable and curable. It is preventable by removing the precancerous colon polyps. It is curable if detected early when it can be surgically removed before it has spread to other parts of the body. If screening and surveillance programs were practiced universally, there would be a tremendous reduction in the incidence and mortality of colon cancer.
Cancer, endometrial:  Cancer of the uterus. Endometrial cancer occurs most often in women between the ages of 55 and 70 years. It accounts for about 6% of cancer in women. Women at elevated risk for endometrial cancer include those who are obese, who have few or no children, who began menstruating at a young age, who had a late menopause, and women of high socioeconomic status. It is thought that most of these risk factors are related to hormones, especially excess estrogen. It is now recognized that the ratio of certain estrogens to each other is of critical importance in estimating risk.
Cancer, esophageal:  A malignant tumor of the esophagus. The risk of cancer of the esophagus is increased by long-term irritation of the esophagus, such as from smoking, heavy alcohol intake, and Barrett esophagitis. The risk of esophageal cancer rises with the number of cigarettes smoked per day and the duration of smoking. A history of radiotherapy to the area, such as for the treatment of breast cancer or lymphoma, also predisposes to esophageal cancer. Very small tumors in the esophagus usually do not cause symptoms. As a tumor grows, the most common symptom is difficulty in swallowing. There may be a feeling of fullness, pressure, or burning as food goes down the esophagus. Problems with swallowing may come and go. At first, they may be noticed mainly when the person eats meat, bread, or coarse foods, such as raw vegetables. As the tumor grows larger and the pathway to the stomach becomes narrower, even liquids can be hard to swallow, and swallowing may be painful. Cancer of the esophagus can also cause indigestion, heartburn, vomiting, and frequent choking on food. Because of these problems, weight loss is common. Esophageal cancer can be diagnosed through a barium X-ray study of the esophagus and endoscopy and biopsy of the tumor. Treatment includes chemotherapy and sometimes surgery. The prognosis (outlook) with esophageal cancer is guarded. At the time of the diagnosis, more than 50% of patients have unresectable (unremovable) tumors or evidence of metastases.
Cancer, gastric:  Worldwide, stomach cancer is the second most frequent cancer and the second leading cause of death from cancer. It can develop in any part of the stomach and spread to other organs. Duodenal ulcers (peptic ulcers) are not associated with stomach cancer. However, infection with a bacterium called Helicobacter pylori is associated with gastric cancer. In one study, gastric cancer developed in about 3% of the infected patients and none of the uninfected patients. Eradication of the bacterium prevents or delays the development of gastric cancer. The risk of gastric cancer is also increased in Down syndrome. Symptoms of stomach cancer are often vague, such as loss of appetite and weight, so diagnosis is often delayed. The cancer is diagnosed definitively with a biopsy of stomach tissue. Cancer of the stomach is difficult to cure unless it is found early. Treatment may include surgery, chemotherapy and radiotherapy. Surgery is the most common treatment. It involves removal of part (subtotal or partial gastrectomy) or all (total gastrectomy) of the stomach.
Cancer, Hodgkin disease (adult):  A type of lymphoma (cancer of the lymphatic system). The most common symptom of Hodgkin disease is a painless swelling in the lymph nodes in the neck, underarm, or groin. Hodgkin disease is diagnosed when abnormal tissue is detected by a pathologist after a biopsy of an enlarged lymph node. Treatment usually includes radiation therapy or chemotherapy. Regular follow-up examinations are important after treatment for Hodgkin disease. Patients treated for Hodgkin disease have an increased risk of developing other types of cancer later in life, especially leukemia.
Cancer, Islet cell:  A rare but highly treatable type of pancreatic cancer that begins in the cells of the pancreas that produce insulin and other hormones. Islet cell cancer can cause the pancreas to produce too much insulin or other hormones. When this happens, the patient may feel weak or dizzy and may have chills, muscle spasms, and diarrhea as well as pain in the stomach or abdomen. Islet cell cancer is also called islet cell carcinoma.
Cancer, kidney:  Malignancy of the kidney, the organ that is primarily responsible for the removal of metabolic products from the body. The types of kidney cancer in adults and children are different and distinct: Adults - Kidney cancer tends to occur after age 50 and strikes men twice as often as women. The most common type occurs in the renal (kidney) tissue that filters the blood and produces the urine and is called renal cell cancer (or renal cell carcinoma). Another type of adult kidney tumor arises in the renal pelvis where the urine collects and is called transitional cell carcinoma. The most frequent diagnostic sign of kidney cancer in adults is blood in the urine. Children - Far and away the main type of kidney cancer in children is Wilms tumor. It starts to develop in fetal life and may be large by the time it is detected (on the average at 3 years of age). Wilms tumor is associated with certain congenital defects including urinary tract abnormalities, absence of the iris (aniridia) and hemihypertrophy (enlargement of one side of the body), and shows an increased incidence among siblings and twins. The tumor tends to cause a noticeable mass and sometimes pain in the abdomen. Blood in the urine (hematuria) occurs in a minority of cases.
Cancer, larynx:  Cancer of the voice box (the larynx) which is located at the top of the windpipe (trachea). Also called laryngeal cancer or laryngeal carcinoma. Cancer of the larynx occurs most often in people over the age of 55 years. A clear association has been made between smoking, excess alcohol ingestion, and laryngeal cancer. If a patient with laryngeal cancer continues to smoke and drink alcoholic beverages, the likelihood of a cure is diminished, and the risk of developing a second tumor is enhanced. People who stop smoking and drinking can greatly reduce their risk of cancer of the larynx. The larynx is divided into 3 anatomical regions. From top to bottom, they are the supraglottis, the glottis (which contains the vocal cords), and the subglottis. The supraglottic area is rich in lymphatic drainage so up to half of people with supraglottic tumors already have metastases (spread of the tumor) to lymph nodes at the time of diagnosis. The vocal cords are largely devoid of lymphatic vessels so that cancer confined to the vocal cords rarely, if ever, presents with involved lymph nodes. Subglottic tumors are quite rare but may metastasize. Painless hoarseness can be a symptom of cancer of the larynx. The larynx can be examined with a viewing tube called a laryngoscope. Cancer of the larynx is usually treated with radiation therapy or surgery. Chemotherapy can also be used for cancers that have spread.
Cancer, leukemia:  Leukemia is a cancer of the white blood cells. Leukemias are grouped by how quickly the disease develops (acute or chronic) as well as by the type of blood cell that is affected. People with leukemia are at significantly increased risk for developing infections, anemia, and bleeding. Diagnosis of leukemia is supported by findings of the medical history and examination, and examining blood under a microscope. Leukemia cells can be detected and further classified with a bone marrow aspiration and/or biopsy. Most patients with leukemia are treated with chemotherapy. Some patients also may have radiation therapy and/or bone marrow transplantation.
Cancer, lung:  kills more men and women than any other form of cancer. Since the majority of lung cancer is diagnosed at a relatively late stage, only 10% of all lung cancer patients are ultimately cured. Eight out of 10 lung cancers are due to tobacco smoke. Lung cancers are classified as either small cell or non-small cell cancers. Persistent cough and bloody sputum can be symptoms of lung cancer. Lung cancer can be diagnosed based on examination of sputum, or tissue examination with biopsy using bronchoscopy, needle through the chest wall, or surgical excision.
Cancer, lymphoma, Hodgkin (adult):  A type of lymphoma (cancer of the lymphatic system). The most common symptom of Hodgkin disease is a painless swelling in the lymph nodes in the neck, underarm, or groin. Hodgkin disease is diagnosed when abnormal tissue is detected by a pathologist after a biopsy of an enlarged lymph node. Treatment usually includes radiation therapy or chemotherapy. Regular follow-up examinations are important after treatment for Hodgkin disease. Patients treated for Hodgkin disease have an increased risk of developing other types of cancer later in life, especially leukemia - due to the carcinogenic effect of the treatment itself.
Cancer, lymphoma, non-Hodgkin:  A lymphoma is a cancer that develops in the lymphatic system. The most common symptom of non-Hodgkin lymphomas is a painless swelling in the lymph nodes in the neck, underarm, or groin. Non-Hodgkin lymphomas are diagnosed with a biopsy of an enlarged lymph node. The distinction between Hodgkin and non-Hodgkin is made by microscopy. Follow-up examinations are important after lymphoma treatment. Most relapses occur in the first 2 years after therapy.
Cancer, male, breast:  Male breast cancer is much less common than breast cancer in women. Fewer than 1% of persons with breast cancer are male. However, breast cancer is no less dangerous in males than in females. After the diagnosis of breast cancer is made, the mortality rates are virtually the same for men and for women. Male breast cancer tends to occur after age 50. Men taking estrogen or naturally producing higher levels of the hormone are at increased risk, as are men with Klinefelter syndrome, which results in low testicular function. As with women, men with relatives who carry the breast cancer gene are at elevated risk. And as with breast cancer in women, black men are more likely than white men to die of the disease. About 175,000 women will be diagnosed with breast cancer annually in the US and 40,000 of these women will die of the disease. By comparison, breast cancer will be diagnosed in about 1,500 men this year and 400 of these men will die of their disease.
Cancer, malignant melanoma:  A skin cancer that begins in cells called melanocytes that can grow together to form benign (not cancerous) moles. A change in size, shape, or color of a mole can be a sign of melanoma. Melanoma can be cured if detected early, before spread to other areas of the body. Diagnosis is confirmed with a biopsy of the abnormal skin. Sun exposure can cause skin damage that can lead to melanoma.
Cancer, multiple myeloma:  A bone marrow cancer involving a type of white blood cell called a plasma (or myeloma) cell. The tumor cells can form a single collection (a plasmacytoma) or many tumors (multiple myeloma). Plasma cells are part of the immune system and make antibodies. Because patients have an excess of identical plasma cells, they have too much of one type of antibody. This form of antibody is called para-protein and it is present in blood and/or urine in about 99% of cases. Normal antibody levels are almost always reduced and this, combined with a slight reduction in the number of neutrophils, leads to a susceptibility to infection which may be life threatening. As myeloma cells increase in number, they damage and weaken the bones, causing pain and often fractures. When bones are damaged, calcium is released into the blood leading to hypercalcemia (excess calcium in the blood) and that causes loss of appetite, nausea, thirst, fatigue, muscle weakness, restlessness, and confusion. Myeloma cells prevent the bone marrow from forming normal plasma cells and other white blood cells important to the immune system so patients may not be able to fight infections. The cancer cells can also prevent the growth of new red blood cells, causing anemia. Excess antibody proteins and calcium may prevent the kidneys from filtering and cleaning the blood properly.
Cancer, non-small cell lung:  Cancer of the lung which is not of the small cell carcinoma (oat cell carcinoma) type. The term "non-small cell lung cancer" is generally applied to the various types of bronchogenic carcinomas (those arising from the lining of the bronchi) which include adenocarcinoma, squamous cell carcinoma, and large cell undifferentiated carcinoma. The distinction between small cell and non-small cell cancer is important for proper treatment. Surgery is the treatment of choice for the early stage of non-small-cell lung cancer.
Cancer, oat (small) cell:  A type of lung cancer in which the cells are small, round and resemble oats. Also called small cell lung cancer.
Cancer, oral:  Cancer of the mouth area. A sore in the mouth that does not heal can be a warning sign of oral cancer. A biopsy is the only to know whether an abnormal area in the oral cavity is cancer. Oral cancer is caused by tobacco (smoking and chewing) and alcohol use. Surgery to remove the tumor in the mouth is the usual treatment for patients with oral cancer.
Cancer, ovary:  Cancer of the ovary, the egg sac of females. Most ovarian tumors in women under age 30 are benign, fluid- filled cysts. These cysts are not cancerous. There are several types of ovarian cancer. Ovarian cancer that begins on the surface of the ovary (epithelial carcinoma) is the most common type. Women who have a family history of ovarian cancer are at an increased risk of developing ovarian cancer. Hereditary ovarian cancer makes up approximately 5 to 10% of all cases of ovarian cancer. Three hereditary patterns have been identified: ovarian cancer alone, ovarian and breast cancers, and ovarian and colon cancers. Ovarian cancer is hard to detect early because there usually are no symptoms and those symptoms that do occur tend to be vague. Detection of ovarian cancer involves pa including pelvic exam, ultrasound, x-ray tests, CA-125 blood test and biopsy of the ovary.
Cancer, pancreas:  Pancreatic cancer has been called a "silent" disease because early pancreatic cancer usually does not cause symptoms. If the tumor blocks the common bile duct and bile cannot pass into the digestive system, the skin and whites of the eyes may become yellow (jaundiced), and the urine darker as a result of accumulated bile pigment called bilirubin.
Cancer, papillary:  Cancer of a structure called the papilla or ampulla of Vater, a small muscle located at the junction where the common bile duct (carrying bile from the liver and secretions from the pancreas) empties into the duodenum (upper small intestine). Because of its location, this cancer can cause obstruction of the common bile duct and prevent bile from flowing into the intestine and out of the body. The chemicals usually eliminated from the body in bile -— in particular, bilirubin -- accumulate in the blood and cause jaundice (yellow skin and eyes) and itching. The stool becomes light-colored and the urine dark-colored since the accumulating bilirubin (which is yellow to dark brown) is eliminated in the urine instead of the stool. The treatment is surgical removal of the cancer. There is no effective chemotherapy for ampullary cancer. The cause of ampullary carcinoma is unknown. Fortunately, it is rather rare.
Cancer, penis:  Cancer of the penis is a disease in which malignant cells originate in the tissues of the penis. Cancer of the penis is rare in the United States. Men who are not circumcised at birth may have a higher risk for getting cancer of the penis.
Cancer, prostate:  Cancer of the gland that produces some of the components of semen fluid. Prostate cancer is the second leading cause of death of males in the U.S. Prostate cancer is often first detected as a hard nodule during a routine rectal examination. The PSA (prostate specific antigen) blood test is a screening test for prostate cancer. Diagnosis of prostate cancer is established when cancer cells are identified in prostate tissue obtained by a biopsy. In some patients, prostate cancer is life threatening. In many others, prostate cancer can exist for years without causing any health problems. In electing to have treatment or not it is important to factor in the patient's age and general condition. In older men prostate cancer tends to be slow growing and it may be that the patient is not likely to outlive the cancer - in other words if the probability that some other illness will end a person's life before the prostate cancer is likely to achieve that effect, it may make sense to do nothing.
Cancer, rectum:  A malignant tumor arising from the inner wall of the end (rectum) of the large intestine. The third leading cause of cancer in males, fourth in females in the U.S. Risk factors for cancer of the colon and rectum (colorectal cancer) include heredity, colon polyps, and long standing ulcerative colitis. Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer. Colon polyps and early cancer can have no symptoms. Therefore, regular screening is important. Diagnosis can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue. Surgery is the most common treatment for colorectal cancer.
Cancer, skin:  Cancer of the outer surface of the body. The most common cancer in the U.S. There are many types of skin cancer. Ultraviolet light from sunlight is the main cause of skin cancer. Unexplained changes in the appearance of the skin, lasting longer than 2 weeks, should be evaluated by a doctor.
Cancer, stomach:  Worldwide, stomach cancer is the second most frequent cancer and the second leading cause of death from cancer. It can develop in any part of the stomach and spread to other organs. It is also known as gastric cancer. Infection with a bacterium called Helicobacter pylori is associated with gastric cancer. In one study, gastric cancer developed in about 3% of the infected patients and none of the uninfected patients. Eradication of the bacterium prevents or delays the development of gastric cancer. The risk of gastric cancer is also increased in Down syndrome. Symptoms of stomach cancer are often vague, such as loss of appetite and weight, so diagnosis is often delayed. The cancer is diagnosed definitively with a biopsy of stomach tissue. Cancer of the stomach is difficult to cure unless it is found early. Treatment may include surgery, chemotherapy and radiotherapy. Surgery is the most common treatment. It involves removal of part (subtotal or partial gastrectomy) or all (total gastrectomy) of the stomach.
Cancer, testicles:  Cancer of the male sex organ (testicle) that normally produces the hormone testosterone. One of the most common cancers in young men. Most testicular cancers are found by men themselves as a lump in the testicle. The risk of cancer of the testicles is increased in males whose testicles did not move down normally into the scrotum (holding sac for the testicles) during development if the problem is not corrected in early childhood. This condition is referred to as undescended testicles. When a growth in the testicle is detected, cancer is confirmed after surgical removal of the affected testicle (orchiectomy) and examination of the tissue under a microscope. Testicular cancer is almost always curable if it is found early.
Cancer, thyroid:  Cancer of the gland in front of the neck that normally produces thyroid hormone which is important to the normal regulation of the metabolism of the body. There are four major types of thyroid cancer -- papillary, follicular, medullary, and anaplastic. Persons who received radiation to the head or neck in childhood should be examined by a doctor every 1 to 2 years. The most common symptom of thyroid cancer is a lump, or nodule, that can be felt in the neck. The only certain way to tell whether a thyroid lump is cancer is by examining the thyroid tissue obtained using a needle or surgery for biopsy.
Cancer, uterus:  Cancer of the uterus. Also called endometrial cancer. Cancer of the uterus occurs most often in women between the ages of 55 and 70 years. It accounts for about 6% of cancer in women. Women at elevated risk for uterine cancer include those who are obese, who have few or no children, who began menstruating at a young age, who had a late menopause, and women of high socioeconomic status. It is thought that most of these risk factors are related to hormones, especially excess estrogen.
Candida albicans:  (also called Monilia albicans) A yeast-like fungal organism found in small amounts in the normal human intestinal tract. Normally kept in check by the body's own helpful bacteria, Candida albicans can increase in numbers when this balance is disturbed to cause candidiasis of the intestinal tract, or yeast infections of other parts of the body. C. albicans causes thrush. Although not fully recognized by mainstream medicine, chronic candidiasis can cause myriad systemic systems the most common of which is fatigue and poor digestion. When this happens it is called the yeast syndrome.
Candidemia:  Bloodstream infection with Candida, a yeast-like fungus. Persons at high risk for candidemia include low-birth-weight babies, surgical patients, and those whose immune systems are deficient. Treatment of fulminant candidemia is with the antifungal agent amphotericin B. This is a life threatening emergency condition. The more usual situation is chronic subacute candidemia which should not be treated with Amphotericin B because of its life-threatening side-effects. Chronic subacute candidemia must be treated with the German isopathic (SanPharma) remedies.
Candidiasis:  Overgrowth of the C. albicans yeast in the gastrointestinal tract, or infection of other body areas with this yeast. Vaginal yeast infections, some forms of diaper rash and other skin rashes that emerge in moist, warm areas of skin, and thrush (a condition characterized by patches of white inside the mouth and/or throat) are all forms of yeast infection. Candidiasis tends to develop when the normal acid/base balance of the mesodermal (connective tissue) comparment is upset, or when the normal flora of the body is dysregulated as can occur with antibiotic use. Prevention measures include alkalinization and the use of probiotics and in some cases dietary changes. Treatment can include antifungal medications, notably Nystatin for non-invasive conditions and Amphotericin B for invasive candidiasis. Candidiasis is usually a minor and easily addressed problem, but can be more serious for those with immune-system disorders, such as AIDS. If it progresses to yeast syndrome, treatment can require weeks or months.
Candidiasis, invasive:  A fungal infection that occurs when Candida enters the bloodstream and then spreads through the body. Candida is the fourth most common cause of bloodstream infection among hospitalized patients in the US. A survey found that candidemia (bloodstream infection with Candida) occurs in 8 of every 100,000 persons per year. Persons at high risk for candidemia include low-birth-weight babies, surgical patients, and those whose immune systems are deficient. The symptoms of invasive candidiasis are not specific. Fever and chills that do not improve after antibiotic therapy are the most common symptoms. If the infection spreads to deep organs such as kidneys, liver, bones, muscles, joints, spleen, or eyes, additional specific symptoms may develop, which vary depending on the site of infection. If the infection does not respond to treatment, the patient’s organs may fail and cause death. Invasive candidiasis may result when a person’s own Candida organisms, normally found in the digestive tract, enter the bloodstream. On rare occasions, it can also occur when medical equipment or devices become contaminated with Candida. In either case, the infection may spread throughout the body. Invasive candidiasis is usually diagnosed by either culture of blood or tissue or by examining samples of infected tissue under the microscope. Invasive candidiasis is usually treated with an antifungal agent called amphotericin B that is given intravenously(IV) (in the vein) or it may be treated with the azole drugs taken by mouth or IV.
Candidiasis, oral:  Yeast infection of the mouth and throat caused by Candida albicans; also known as thrush. Yeast organisms are part of the germs normally found in various parts of the body. They ordinarily do not cause any symptoms. Certain conditions, such as antibiotic use and other immunosuppresants, can disturb the natural balance of microbes in the mouth and allow an overgrowth of Candida to cause thrush.
Canker sores:  small ulcer craters in the lining of the mouth that are frequently painful and sensitive. About 20% of the population (1 out of 5) people have canker sores at any one time. Canker sores are also medically known as aphthous ulcers. Women are more likely than men are to have recurrent canker sores. Genetic studies show that susceptibility to recurrent outbreaks of the sores is inherited in some patients. This partially explains why family members often share the condition. Canker sores are usually found on the movable parts of the mouth such as the tongue or the inside lining of the lips and cheeks.
Cannabinoid:  A chemical compound in cannabis. or marijuana. Tetrahydrocannabinol is one of the cannabinoids.
Cannabinoid receptor 1:  One of the two known receptors in the endocannabinoid (EC) system associated with the intake of food and tobacco dependency. Blocking the cannabinoid receptor 1 (CNR1) may reduce dependence on tobacco and the craving for food. The gene encoding CNR1 is located in chromosome region 6q14-q15. Also called the CB1 receptor or CB1.
Cannabinoid receptor 2:  One of the two known receptors in the endocannabinoid (EC) system. The gene encoding cannabinoid receptor 2 (CNR2) is located on chromosome 1. Also known as the CB2 receptor or CB2.
Cannabis:  The botanical name for the plant from which marijuana comes. Its full name is Cannibis sativa. Use of cannabis produces a mild sense of euphoria, as well as impairments in judgment and lengthened response time. Cannabis may be smoked or eaten. Although cannabis use is illegal in most parts of the world, the plant appears to have some potential for medical use, particularly as a palliative for glaucoma and disease-related loss of appetite, as is often seen in cancer, AIDS, and other illnesses. In some areas of the US, individuals whose physicians recommend the medical use of cannabis can obtain special permission.
Cannonball pulse:  A jerky pulse that is full and then collapses because of aortic insufficiency (when blood ejected into the aorta regurgitates back through the aortic valve into the left ventricle). This type of pulse was likened to a water hammer, a Victorian toy consisting of a glass tube filled partly with water or mercury in a vacuum. The water or mercury produced a slapping impact when the glass tube was turned over. Also called a Corrigan pulse or a water hammer pulse, collapsing, pistol-shot, or trip-hammer pulse.
Cannula:  A slender tube that can be inserted into a body cavity or duct. During the insertion of the cannula, its lumen (interior) is usually occupied by a trocar, a solid shaft, to stiffen it. The word "cannula" is the diminutive of the Latin "canna" (reed) = a little reed.
Capillaries:  Capillaries are the smallest of blood vessels. They serve to distribute oxygenated blood from arteries to the tissues of the body and to feed deoxygenated blood from the tissues back into the veins. The capillaries are thus a central component in the circulatory system, essentially between the arteries and the veins. When pink areas of skin are compressed, this causes blanching because blood is pressed out of the capillaries. The blood is the fluid in the body that contains, among other elements, the red blood cells (erythrocytes) that carry the oxygen and give the blood its red color.
Caps:  Abbreviation for capsules. One of a number of hallowed abbreviations of terms that have traditionally been used in prescriptions.
Capsaicin:  A component of certain plants, including cayenne and red pepper, used topically to relieve minor arthritis pain and nerve pain. Capsaicin is made into creams and applied to the skin. It appears to work by reducing a chemical substance found at nerve endings that is involved in transmitting pain signals to the brain.
Capsid:  The protein coat of a virus.
Capsule:  Capsule has many meanings in medicine including the following: 1. In medicine, a membranous structure that envelops an organ, a joint, tumor, or any other part of the body. It is usually made up of dense collagen-containing connective tissue. 2. In pharmacy, a solid dosage form in which the drug is enclosed in a hard or soft soluble container, usually of a form of gelatin. 3. In microbiology, a coat around a microbe, such as a bacterium or fungus.
Capsule of Glisson:  The capsule of the liver. A layer of connective tissue surrounding the liver and ensheathing the hepatic artery, portal vein, and bile ducts within the liver. Named for the British physician, anatomist, physiologist, and pathologist Francis Glisson (1597-1677).
Capsulitis:  Inflammation of the capsule of the ocular lens, or a joint, or the liver.
Carb:  Slang for carbohydrate.
Carbo-loading:  An eating routine used by some athletes that involves downing large amounts of carbohydrates several days before a potentially exhausting endurance event. Carbo-loading has no known potential benefits for anyone except athletes under these special circumstances.
Carbohydrate:  Mainly sugars and starches, together constituting one of the three principal types of nutrients used as energy sources (calories) by the body. Carbohydrates can also be defined chemically as neutral compounds of carbon, hydrogen and oxygen. Carbohydrates come in simple carbohydrates such as sugars and in complex forms such as starches and fiber. The body breaks down most sugars and starches into glucose, a simple sugar that the body can use to feed its cells. Complex carbohydrates are derived from plants. Dietary intake of complex carbohydrates can lower blood cholesterol when they are substituted for saturated fat.
Carbolic acid:  A synonym of phenol. In dilute solution, an antimicrobial agent. First used to clean wounds and dress them by the surgeon Joseph Lister who reported in 1867 that his wards at the Glasgow Royal Infirmary had remained free of sepsis, then a great scourge, for 9 months. Carbolic acid or phenol is also a proliferant (provokes the regeneration of connective tissue) used in prolotherapy, a technique for treating connective tissue injuries - back syndromes, etc.
Carbon dioxide:  A gas which is the byproduct of cellular metabolism and which collects in the tissues, is cleared from the tissues by the blood within the veins, is carried by the hemoglobin in the red blood cells, and removed from the body via the lungs in the exhaled air. Abbreviated CO2.
Carbon dioxide content:  A measure of the bicarbonate level in the blood. Higher than normal carbon dioxide levels may reflect excessive loss of acid (as with recurrent vomiting or continuous gastric drainage) or acid-base disorders (such as primary aldosteronism and Cushing syndrome). Lower than normal carbon dioxide levels are common in acidosis (as in diabetic ketoacidosis, kidney disease, and severe diarrhea) or respiratory alkalosis in which too much carbon dioxide is blown off, for example, by hyperventilating.
Carbon monoxide hemoglobin:  Hemoglobin that has carbon monoxide instead of the normal oxygen bound to it. Carbon monoxide has a much great affinity than oxygen for hemoglobin. Carbon monoxide hemoglobin is formed in carbon monoxide poisoning. The source of the carbon monoxide may be exhaust (such as from a car, truck, boat or generator), smoke from a fire, or tobacco smoke. Also known as carboxyhemoglobin. The level of carbon monoxide hemoglobin is a measure of the degree of carbon monoxide exposure. The presence of carbon monoxide hemoglobin in the blood is called carboxyhemoglobinemia.
Carbon monoxide poisoning:  Poisoning with carbon monoxide, a tasteless odorless gas that is a byproduct of combustion. Carbon monoxide acts as a poison by competing with oxygen for binding sites on hemoglobin, the molecule in red blood cells that carries oxygen from the lungs to the more remote tissues of the body and returns carbon dioxide from the tissues to the lungs. On inhalation, carbon monoxide binds to hemoglobin with a binding affinity 200-270 times greater than that of oxygen. Carbon monoxide poisoning may be more common than is currently recognized. It is conservatively estimated that in the US there are at least 200 deaths per year from carbon monoxide poisoning. The tennis star Vitas Gerulaitis died when his Long Island cottage was filled with carbon monoxide from a swimming pool heater in 1994. Patients may have symptoms of carbon monoxide poisoning but be unaware of the basis of their symptoms. The early symptoms are quite nonspecific. They can resemble the symptoms of motion sickness or heat exhaustion and include prolonged headache, nausea, dizziness, and vomiting. At higher concentrations of carbon monoxide in the blood, the signs of carbon monoxide poisoning can include seizures, coma, and death. These can occur after just minutes of even outdoor exposure to exhaust. The first aid treatment of carbon monoxide poisoning is to move the victim to fresh air away from the source of carbon monoxide AND summon emergency medical service. The medical treatment for carbon monoxide poisoning is oxygen, usually with a face mask. The carbon monoxide levels in the blood are checked until they are low enough for safety. For severe carbon monoxide poisoning, a hyperbaric oxygen chamber may be used to achieve higher doses of oxygen.
Carboxyhemoglobin:  Hemoglobin that has carbon monoxide instead of the normal oxygen bound to it. Carbon monoxide has a much great affinity than oxygen for hemoglobin. Carboxyhemoglobin is formed in carbon monoxide poisoning. The source of the carbon monoxide may be exhaust (such as from a car, truck, boat or generator), smoke from a fire, or tobacco smoke. The level of carboxyhemoglobin is a measure of the degree of carbon monoxide exposure. Also called carbon monoxide hemoglobin.
Carboxyhemoglobinemia:  The presence of carboxyhemoglobin in the blood. Carboxyhemoglobin, hemoglobin that has carbon monoxide bound to it, is formed in carbon monoxide poisoning, as from exhaust (such as from a car, truck, boat or generator), smoke from a fire, or tobacco smoke.
Carbuncles:  A skin abscess, a collection of pus that forms inside the body. Antibiotics are often not very helpful in treating abscesses. The main treatments include hot packs and draining ("lancing") the abscess, but only when it is soft and ready to drain.
Carcinoembryonic antigen:  Carcinoembryonic antigen (CEA) is a protein found in many types of cells but associated with tumors and the developing fetus. Carcinoembryonic" reflects the fact that CEA is made by some cancers ("carcino-") and by the developing fetus ("-embryonic"). CEA is tested in blood. The normal range is <2.5 ng/ml in an adult non-smoker and <5.0 ng/ml in a smoker. (< means "less than.") Benign conditions that can increase CEA include smoking, infection, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, and some benign tumors (in the same organs which have cancers with increased CEA). Benign disease does not usually cause a CEA increase over 10 ng/ml. The main use of CEA is as a tumor marker, especially with intestinal cancer. The most common cancers that elevate CEA are in the colon and rectum. Others: cancer of the pancreas, stomach, breast, lung, and certain types of thyroid and ovarian cancer. Levels over 20 ng/ml before therapy are associated with cancer which has already metastasized (spread). CEA is useful in monitoring the treatment of CEA-rich tumors. If the CEA is high before treatment, it should fall to normal after successful therapy. A rising CEA level indicates progression or recurrence of the cancer. Chemotherapy and radiation therapy can themselves cause a rise in CEA due to death of tumor cells and release of CEA into the blood stream but that rise is typically temporary.
Carcinogen:  A substance or agent that causes cancer. Related terms include the adjective "carcinogenic" and the nouns "carcinogenesis" and "carcinogenicity." One of the best-known carcinogens is ionizing radiation. The International Agency for Research on Cancer has classified some 60 substances and processes as probably or definitely carcinogenic in humans. These substances and processes are divided into three categories -- Agents and groups of agents, Mixtures, and Exposure circumstances - and they are as follows:

Agents and groups of agents

Aflatoxins, naturally occurring
4-Aminobiphenyl
Arsenic and arsenic compounds
Asbestos
Azathioprine
Benzene
Benzidine
Beryllium and beryllium compounds
N,N-Bis(2-chloroethyl)-2-naphthylamine (chlornaphazine)
Bis(chloromethyl) ether and chloromethyl methyl ether
1,4-Butanediol dimethanesulfonate (busulfan; Myleran)
Cadmium and cadmium compounds
Chlorambucil
1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (methyl-CCNU; Semustine)
Chromium [VI] compounds
Cyclosporine
Cyclophosphamide
Diethylstilbestrol
Erionite
Ethylene oxide
Melphalan
Methoxypsoralen (methoxsalen) plus ultraviolet radiation
MOPP and other combined chemotherapy including alkylating agents
Mustard gas (sulfur mustard)
2-Naphthylamine
Nickel compounds
Estrogen therapy, postmenopausal
Radon and its decay products
Silica, crystalline
Solar radiation
Talc-containing asbestiform fibers
2,3,7,8-Tetrachlorodibenzo-para-dioxin
Thiotepa
Treosulfan
Vinyl chloride

Mixtures
Alcoholic beverages
Analgesic mixtures containing phenacetin
Betel quid with tobacco
Coal-tar pitches
Coal tars
Mineral oils, untreated and mildly treated
Salted fish (Chinese style)
Shale oils
Soots
Tobacco products, smokeless
Tobacco smoke
Wood dust

Exposure circumstances
Aluminum production
Auramine manufacturing
Boot and shoe manufacture and repair
Coal gasification
Coke production
Furniture and cabinet making
Hematite mining (underground) with exposure to radon
Iron and steel founding
Isopropanol manufacturing (strong-acid process)
Magenta manufacturing
Painting (occupational exposure)
Rubber industry
Strong-inorganic-acid mists containing sulfuric acid (occupational exposure)

Carcinoid syndrome:  A syndrome due to carcinoid tumor which secretes large amounts of the hormone serotonin. The syndrome is directly due to the serotonin. Features include flushing and blushing, swelling of the face (especially around the eyes), flat angiomas (little collections of dilated blood vessels) on the skin, diarrhea, bronchial spasm, rapid pulse, low blood pressure and tricuspid and pulmonary stenosis (narrowing of the tricuspid and pulmonic valves of the heart), often with regurgitation. Carcinoid tumor usually arises in the gastrointestinal tract, anywhere between the stomach and the rectum (the favorite spot is in the appendix) and from there may metastasize to the liver. In the liver the tumor produces and releases large quantities of serotonin into the systemic bloodstream.
Carcinoma:  Cancer that begins in the skin or in tissues that line or cover body organs. For example, carcinoma can arise in the breast, colon, liver, lung, prostate, and stomach.
Carcinoma in situ:  Cancer that involves only the place in which it began and that has not spread. Carcinoma in situ is an early-stage tumor. For example, squamous cell carcinoma in situ (Bowen's disease) is an early cancer of the skin. It develops from squamous cells which are flat, scale-like cells in the outer layer of the skin (the epithelium).
Carcinoma in situ, squamous cell:  An early stage of skin cancer. Also known as Bowen's disease. This is a tumor that develops from the squamous cells which are flat, scale-like cells in the outer layer of the skin (the epithelium). The term "in situ" (borrowed from the Romans) means "in the natural or normal place" and, in the case of cancer, it says that the tumor cells are still confined to the site where they originated and they have neither invaded neighboring tissues nor metastasized afar. The hallmark of squamous cell carcinoma in situ is a persistent, progressive, slightly raised, red, scaly or crusted plaque. Bowen's disease may occur anywhere on the skin surface (or on mucosal surfaces such as the mouth). Under the microscope, atypical squamous cells are seen to have proliferated through the whole thickness of the epidermis (the outer layer of the skin) but to have gone no farther. The cause of Bowen's disease classically was prolonged exposure to arsenic. Today, Bowen's disease occurs most often in the sun-exposed areas of the skin in older white males. Treatment options include freezing with liquid nitrogen, cauterization (burning), surgical removal, and chemosurgery. Bowen's disease is named after the American dermatologist John Templeton Bowen (1857-1941).
Carcinoma of the breast, infiltrating ductal:  Infiltrating ductal carcinoma is one of several recognized specific patterns of cancer of the breast. It is so named because it begins in the cells forming the ducts of the breast. It is the most common form of breast cancer, comprising 65-85% of all cases. On a mammogram, invasive ductal carcinoma is usually visualized as a mass with fine spikes radiating from the edges (spiculation). It may also appear as a smooth edged lump in the breast. On physical examination, this lump usually feels much harder or firmer than benign causes of lumps in the breast. On microscopic examination, the cancerous cells invade and replace the normal breast tissue.
Carcinoma of the breast, infiltrating lobular:  Infiltrating lobular carcinoma is the second most common type of invasive breast cancer next to infiltrating ductal carcinoma, accounting for 5 to 10% of breast cancer. Infiltrating lobular carcinoma starts in the lobules, the glands that secrete milk, and then infiltrates surrounding tissue. On mammography, a lobular carcinoma can look similar to a ductal carcinoma - a mass with fine spikes radiating from the edges (spiculation). However, on physical examination of the breast, a lobular carcinoma is usually not a hard mass like a ductal carcinoma but rather a vague thickening of the breast tissue. Lobular carcinoma can occur in more than one site in the breast (as a multicentric tumor) or in both breasts at the same time (as bilateral lobular carcinoma).
Carcinoma, ampullary:  Cancer of a structure called the ampulla of Vater, a small muscle located at the junction where the common bile duct (carrying bile from the liver and secretions from the pancreas) empties into the duodenum (upper small intestine). Because of its location, this cancer can cause obstruction of the common bile duct and prevent bile from flowing into the intestine and out of the body. The chemicals usually eliminated from the body in bile — in particular, bilirubin — accumulate in the blood and cause jaundice (yellow skin and eyes) and itching. The stool becomes light-colored and the urine dark-colored since the accumulating bilirubin (which is yellow to dark brown) is eliminated in the urine instead of the stool. The treatment is surgical removal of the cancer. There is no effective chemotherapy for ampullary cancer. The cause of ampullary carcinoma is unknown. Fortunately, it is rather rare.
Carcinoma, basal cell:  The most common type of skin cancer, a disease in which the cancer cells resemble the basal cells of the epidermis, the outer layer of the skin. Basal cell carcinomas usually appear as the classic "sore that doesn't heal." A bleeding or scabbing sore that seems to get somewhat better, then recurs and starts to bleed, may be a basal cell carcinoma. Most basal cell carcinomas are on the face and neck where the skin is exposed to sunlight. However, a fair number show up on parts of the body such as the abdomen, leg, and scalp exposed to little or no sunlight. Basal cell carcinomas typically are locally invasive. They tend to burrow in locally and not metastasize (spread) to distant locations. Small basal cell carcinomas can be removed by being scraped and burned (curettage and electrodesiccation). Larger basal cells can be removed by surgery. Basal cell carcinomas on the scalp, ears, and sides of the nose, as well as those which have come back after being treated, are treated best by Mohs' surgery (progressive excission until only non-cancerous tissue is seen on microscope exam). One basal cell carcinoma means an increased risk of developing another. Prudent sun precautions and annual skin checkups by the doctor are advisable.
Carcinoma, hepatocellular:  A tumor in which the cancer starts during adulthood in cells in the liver. Also called adult primary liver cancer. Primary liver cancer is different from cancer that has metastasized (spread) from another place in the body to the liver. The signs and symptoms may include a hard lump just below the rib cage on the right side (from swelling of the liver), discomfort in the upper abdomen on the right side, pain around the right shoulder blade, or yellowing of the skin (jaundice). There is often an increase in the blood levels of alpha-fetoprotein (AFP) and alkaline phosphatase. A rapid deterioration of liver function may be the only clue to the presence of the tumor. Hepatocellular carcinoma is potentially curable by surgery, but surgery is the treatment of choice for only a small fraction of patients who have localized disease. Laparoscopy may detect metastatic disease, tumor in both lobes of the liver, or an inadequate liver remnant, and avoid the need for open surgery to explore the liver. Therapy other than surgery is best as part of a clinical trial. Such trials evaluate the efficacy of systemic or infusional chemotherapy, hepatic artery ligation or embolization, percutaneous ethanol (alcohol) injection, radiofrequency ablation, cryotherapy (freezing the tumor), and radiolabeled antibodies, often in conjunction with surgical resection (removal) and/or radiation therapy. The prognosis (outlook) depends on the degree of local tumor replacement and the extent of liver function impairment. Primary liver cancer (hepatocellular carcinoma) is the most common cancer in some parts of the world. It is still relatively uncommon in the US but its incidence is rising, principally in relation to the spread of hepatitis B and hepatitis C. People who have a disease of the liver called cirrhosis are also more likely to get adult primary liver cancer. Hepatitis B and C appear to be the most significant causes of hepatocellular carcinoma worldwide. People who have both hepatitis B and hepatitis C may be at a higher risk if they consume more than 3 oz. (80 grams) of alcohol a day. A first-degree relative with hepatocellular carcinoma also increases the risk. Hepatocellular carcinoma is associated with cirrhosis in 50% to 80% of patients; 5% of cirrhotic patients eventually develop hepatocellular cancer. Aflatoxin has also been implicated as a factor in the etiology (causation) of primary liver cancer in parts of the world where this mycotoxin occurs in high levels in food. Workers exposed to vinyl chloride before controls on vinyl chloride dust were instituted developed sarcomas in the liver, most commonly angiosarcomas.
Carcinoma, Islet cell:  rare but highly treatable type of pancreatic cancer that begins in the cells of the pancreas that produce insulin and other hormones. Islet cell cancer can cause the pancreas to produce too much insulin or other hormones. When this happens, the patient may feel weak or dizzy and may have chills, muscle spasms, and diarrhea as well as pain in the stomach or abdomen.
Carcinoma, Merkel cell:  An infrequent but highly malignant type of skin cancer. Characteristically starts in a sun-exposed area (of the head, neck, arms or legs) in whites 60-80 years of age as a firm, painless, shiny lump that can be red, pink, or blue in color and vary in size from less than a quarter of an inch (a half cm) to more than two inches (5 cm) in diameter. The tumor grows rapidly and often metastasizes (spreads) to other parts of the body. Even relatively small tumors are capable of metastasis, particularly to the regional (nearby) lymph nodes. Merkel cell carcinoma follows an aggressive course like that of melanoma, and has a predilection to spread to (in order of frequency) liver, bone, brain, lung, and skin. The prognosis (outlook) is accordingly poor. "Merkel" is often misspelled as "Merkle." The disease is named for the German anatomist and pathologist Friedrich Sigmund Merkel (1845-1919) and is also called neuroendocrine carcinoma of the skin.
Cardiac:  Having to do with the heart.
Cardiac aneurysm:  An outpouching of an abnormally thin portion of the heart wall, usually resulting from scar tissue left by a healed myocardial infarction. Cardiac aneurysms tend to involve the left ventricle because the blood there is under greatest pressure.
Cardiac arrest:  A medical emergency with absent or inadequate contraction of the left ventricle of the heart that immediately causes bodywide circulatory failure. The signs and symptoms include loss of consciousness; rapid shallow breathing progressing to apnea (absence of breathing); profoundly low blood pressure (hypotension) with no pulses that can be felt over major arteries; and no heart sounds. Cardiac arrest is one of the greatest of all medical emergencies. Within several minutes, there is lack of oxygen (tissue hypoxia), leading to multiple organ injury. Unless cardiac arrest is quickly corrected, it is fatal. The most common causes of cardiac arrest are electrical problems in the heart with ventricular fibrillation representing the major type. In ventricular fibrillation, there is loss of coordinated ventricular contractions leading to immediate loss of effective output of blood by the heart, resulting in circulatory arrest.
Cardiac conduction system:  The electrical conduction system that controls the heart rate. This system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood. Among the major elements in the cardiac conduction system are the sinus node, atrioventricular node, and the autonomic nervous system. The sinus node is the heart's natural pacemaker. The sinus node is a cluster of cells situated in the upper part of the wall of the right atrium. The electrical impulses are generated there. (The sinus node is also called the sinoatrial node.) The electrical signal generated by the sinus node moves from cell to cell down through the heart until it reaches the atrioventricular node (the AV node), a cluster of cells situated in the center of the heart between the atria and ventricles. The AV node serves as a gate that slows the electrical current before the signal is permitted to pass down through to the ventricles. This delay ensures that the atria have a chance to fully contract before the ventricles are stimulated. After passing the AV node, the electrical current travels to the ventricles along special fibers embedded in the walls of the lower part of the heart. The autonomic nervous system (the same part of the nervous system as controls the blood pressure) controls the firing of the sinus node to trigger the start of the cardiac cycle. The autonomic nervous system can transmit a message quickly to the sinus node so it in turn can increase the heart rate to twice normal within only 3 to 5 seconds. This quick response is important during exercise when the heart has to increase its beating speed to keep up with the body's increased demand for oxygen. In emergency ("fight or flight") conditions there is an outpouring of adrenalin from the adrenal gland which results in sustained tachycardia (rapid heart beat).
Cardiac defibrillator, implantable:  A device put within the body that is designed to recognize certain types of abnormal heart rhythms (arrhythmias) and correct them. Defibrillators continuously monitor the heart rhythm in order to detect overly rapid arrhythmias such as ventricular tachycardia (rapid regular beating of the ventricles, the bottom chambers of the heart); and ventricular fibrillation (rapid irregular beating of the ventricles). These ventricular arrhythmias impair the pumping efficiency of the heart and greatly raise the risks of fainting (syncope) and sudden cardiac arrest. They tend to develop in people with coronary artery disease and heart muscle diseases (cardiomyopathies). They are life- threatening. A defibrillator can be implanted within the body by far less invasive techniques than in the past because the devices, aside from being more technologically advanced, are smaller. (An implantable defibrillator is about the size of a minicassette). The defibrillator corrects the heart rhythm by delivering precisely calibrated and timed electrical shocks, when needed, to restore a normal heartbeat.
Cardiac index:  A cardiodynamic measure based on the cardiac output, which is the amount of blood the left ventricle ejects into the systemic circulation in one minute, measured in liters per minute (l/min). Cardiac output can be indexed to a patient's body size by dividing by the body surface area (called the BSA) to yield the cardiac index.
Cardiac insufficiency (Heart failure):  Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. There are many causes of congestive heart failure including: (1) coronary artery disease leading to heart attacks and heart muscle weakness, (2) primary heart muscle weakness from viral infections or toxins such as prolonged alcohol exposure, (3) heart valve disease causing heart muscle weakness due to too much leaking of blood or heart muscle stiffness from a blocked valve, and (4) hypertension (high blood pressure). More Rare causes include hyperthyroidism (high thyroid hormone), vitamin deficiency, and excess amphetamine ("speed") use. The aim of therapy is to improve the pumping function of the heart. General treatment includes salt restriction, diuretics (to get rid of excess fluid), digoxin (to strengthen the heart), and other medications. A drug called spironolactone has been found to be a major help in treating congestive heart failure Its beneficial effects are additive to those from ACE inhibitors, another class of drugs commonly relied on in treating heart failure. A pacemaker-like device is also now available to treat heart failure. The implantable device delivers synchronized electrical stimulation to three chambers of the heart, enabling the heart to pump blood more efficiently throughout the body.
Cardiac Limb Syndrome (Holt-Oram syndrome):  A genetic syndrome characterized by the combination of heart disease and malformations of the upper limb. The heart defect is usually an atrial septal defect (ASD) and, less often, a ventricular septal defect (VSD), although other cardiovascular malformations have been reported. The upper limb malformations most often affect the forearm and thumb. The thumb may be absent or it may be a nonopposable fingerlike digit. All gradations in defects in the upper limb and shoulder girdle have been reported.
Cardiac muscle:  A type of muscle with unique features only found in the heart. The cardiac muscle is the muscle of the heart and medically is called the myocardium ("myo-" being the prefix denoting muscle).
Cardiac myocyte:  A heart muscle cell. Sometimes called a myocyte when it is understood that it is in the heart.
Cardiac myxoma:  A benign tumor of the heart and the most common type of heart tumor in adults.
Cardiac output:  The amount of blood that is pumped by the heart per unit time, measured in liters per minute (l/min). The amount of blood that is put out by the left ventricle of the heart in one contraction is called the stroke volume. The stroke volume multiplied by the heart rate is the cardiac output. A normal adult's heart can easily pump 5 quarts (4.7 liters) of blood a minute. That is the cardiac output, the amount of blood the heart pumps through the circulatory system in one minute.
Cardiac rehabilitation:  A program for people with heart disease designed to reduce future heart risks. Cardiac rehabilitation usually consists of nutritional counseling; management of lipid levels, hypertension, weight, and diabetes; smoking cessation; psychosocial interventions; physical activity counseling; and exercise training. Cardiac rehabilitation reduces the risks of subsequent heart attacks and death from other causes. Intravenous chelation therapy with EDTA is a potent aspect of cardiac rehabilitation.
Cardiac septum:  The septum of the heart is the dividing wall between the right and left sides of the heart. That portion of the septum that separates the two upper chambers (the right and left atria) of the heart is termed the atrial (or interatrial) septum while the portion of the septum that lies between the two lower chambers (the right and left ventricles) of the heart is called the ventricular (or interventricular) septum.
Cardiac stress testing, exercise ("Stress Test"):   The exercise cardiac stress testing (ECST) is the most widely used cardiac (heart) screening test. The patient exercises on a treadmill according to a standardized protocol, with progressive increases in the speed and elevation of the treadmill (typically changing at three-minute intervals). During the exercise cardiac stress testing (ECST), the patient's electrocardiogram (EKG), heart rate, heart rhythm, and blood pressure are continuously monitored. If a coronary arterial blockage results in decreased blood flow to a part of the heart during exercise, certain changes may be observed in the EKG (the electrocardiogram), as well as in the response of the heart rate and blood pressure. The accuracy of the ECST in predicting significant coronary artery disease (CAD) depends in part on the "pre-test likelihood" of CAD (also known as Bayes' theorem). In a patient at high risk for CAD (for example, because of advanced age or multiple coronary risk factors), an abnormal ECST is quite accurate (over 90% accurate) in predicting the presence of CAD. However, a relatively normal ECST may not mean there is an absence of significant coronary artery disease in a patient with the same high risk factors (so-called "false negative ECST"). In a patient at low risk for CAD, a normal ECST is quite accurate (over 90%) in predicting the absence of significant CAD. And an abnormal ECST test may not reflect the true presence of CAD (so-called "false-positive ECST"). The ECST may miss the presence of significant CAD and so give a false negative result. Or the ECST may indicate the presence of significant CAD when, in fact, there is none and so yield a false-positive test result. These false-negative and false-positive results are due to a variety of cardiac circumstances, which may include: 1. An abnormal EKG at rest, which may be due to abnormal serum electrolytes, abnormal cardiac electrical conduction, or certain medications, such as digitalis; 2. Heart conditions not related to CAD, such as mitral valve prolapse (drooping) or hypertrophy (increased size) of the heart; or 3. An inadequate increase in the heart rate and/or blood pressure during exercise. If the initial ECST does not clarify the diagnosis, additional tests are often used to clarify the condition. These further options include radionucleide isotope injection and ultrasound of the heart (stress echocardiography) during the stress test.
Cardiac tamponade:  A life-threatening situation in which there is such a large amount of fluid (usually blood) inside the pericardial sac around the heart that it interferes with the performance of the heart. The end result, if untreated, is low blood pressure, shock and death. The excess fluid in the pericardial sac acts to compress and constrict the heart. The word "tamponade" is direct from the French. The French verb "tamponner" means to plug up and, also, to smash into. Here the outpouring of fluid within the pericardial sac is, so to speak, smashing into the heart. Cardiac tamponade can be due to excessive pericardial fluid, a wound to the heart, or rupture of the heart. Also called pericardial tamponade.
Cardiac transplant:  A surgical procedure in which a diseased heart is replaced with a healthy heart from a deceased person. The world's first heart transplant was done on December 3, 1967 by South African surgeon Christiaan Bernard (1922-2001). The recipient was Louis Washkansky, a grocer. The surgery went well. However, Mr. Washkansky was left vulnerable to infection from the large doses of immune-suppressing drugs (azathioprine and hydrocortisone) and radiation he received. He died of pneumonia 18 days after surgery. The second human heart transplant was also done by Dr. Barnard. On Jan. 2, 1968, Dr. Barnard transplanted the heart of a young man into a retired dentist, Philip Blaiberg. (The young man was of "mixed race" while Dr. Blaiberg was white. The fact that Dr. Bernard ignored racial barriers caused a sensation in apartheid South Africa.) The amount of anti-rejection drugs was reduced and Dr. Blaiberg survived for 19 months and 15 days. He died of chronic organ rejection. Heart transplant surgery has now become a standard procedure. It had been done about 100,000 times as of 2001 and was carried out on about 2,100 patients in 160 hospitals in the U.S. in 2001, with a one-year success rate of 85-90% and a five-year success rate of 75%.
Cardiac ventricle:  One of the two lower chambers of the heart. The right ventricle is the chamber that receives blood from the right atrium and pumps it into the lungs via the pulmonary artery while the left ventricle is the chamber that receives blood from the left atrium and pumps it into the system circulation via the aorta.
Cardinoma, pancreatic:  Malignancy of the pancreas. Pancreatic cancer has been called a "silent" disease because early pancreatic cancer usually does not cause symptoms. If the tumor blocks the common bile duct and bile cannot pass into the digestive system, the skin and whites of the eyes may become yellow (jaundiced), and the urine darker as a result of accumulated bile pigment called bilirubin. Cancer of the pancreas has markedly increased in incidence over the decades and now ranks as the fourth leading cause of cancer death in the US. Despite the high mortality rate associated with pancreatic cancer, its causation is poorly understood. Smoking is known to be a major risk factor. Cigarette smokers develop cancer of the pancreas two to three times more often than do nonsmokers. Quitting smoking reduces the risk of pancreatic cancer. Cancer of the pancreas is rarely curable. The overall survival rate is less than 4%. The cure rates are highest (although still usually under 25%) if the tumor is small (less than 2 cm in diameter) and is truly localized to the pancreas but, unfortunately, such cases account for fewer than 20% of all cases of pancreatic cancer. For patients with advanced cancers, the overall survival rate of all stages is less than 1% at 5 years with most patients dying within 1 year. Staging of the tumor is important to the diagnosis and to the identification of patients with disease that cannot be resected (removed by surgery). Staging has been aided by advances in imaging technology, including the spiral computed tomographic (CT) scan, magnetic resonance imaging (MRI) scan, positron emission tomographic (PET) scan, endoscopic ultrasound, and laparoscopic staging. There are no specific tumor markers for pancreatic cancer. Markers such as serum CA 19-9 have low specificity. Most patients with pancreatic cancer have an elevated CA 19-9 at diagnosis. Following or during definitive therapy, the increase of CA 19-9 levels may identify patients with progressive tumor growth. However, the presence of a normal CA 19-9 does not rule out recurrence of the tumor.
Cardiology:  The study and treatment of heart disorders.
Cardiomyopathy:  Disease of the heart muscle (the myocardium). From the Greek roots: cardio-, heart + myo, muscle + pathos, disease = disease (of the) heart muscle.
Cardiomyopathy, dilated:  A disorder in which the chambers of the heart are dilated (enlarged) because the heart muscle is weakened and cannot pump effectively. There are many causes, the most common being myocardial ischemia (not enough oxygen supplied to the heart muscle) due to coronary artery disease.
Cardiomyopathy, doxorubicin:  Heart disease due to the drug doxorubicin (brand name:Adriamycin), a potent broad-spectrum antitumor agent effective in treating a variety of cancers including solid tumors and leukemia. Unfortunately, its clinical use is limited by dose-dependent cardiac side effects that lead to degenerative cardiomyopathy, congestive heart failure, and death. In addition, some adult patients treated with the drug when they were children later develop dilated cardiomyopathy.
Cardiomyopathy, hypertrophic (HCM):  A genetic disorder of the heart characterized by increased thickness (hypertrophy) of the wall of the left ventricle, the largest of the four chambers of the heart. The disease can present at any time in life. It is the leading cause of sudden death in athletes and young people. It is inherited in an autosomal dominant manner. Men and women with HCM stand a 50-50 chance of transmitting the HCM gene to each of their children. Measurement of the thickness of the left ventricle wall can predict who is most at risk for HMC. The test is done by echocardiography, a routine ultrasound test of the heart. Persons with a maximum wall thickness less than three-quarters of an inch (19 mm) are virtually free of risk for fatal cardiac arrest over the next 20 years whereas those with a wall thickness more than 1.2 inches (30 mm) have a 40% chance of fatal cardiac arrest during that time period. Patients in danger can be fitted with implantable defibrillators. Also called familial hypertrophic cardiomyopathy.
Cardiopathy:  Heart disease. A nonspecific term applicable to any and all diseases of the heart. From cardio- + the Greek pathos, disease.
Cardioplegia:  Paralysis of the heart, as may be done electively in stopping the heart during cardiac surgery. Cardioplegia may be done using chemicals, cold (cryocardioplegia) or electrical stimulation.
Cardiopulmonary:  Having to do with both the heart and lungs.
Cardiopulmonary bypass:  Bypass of the heart and lungs as, for example, in open heart surgery. Blood returning to the heart is diverted through a heart-lung machine (a pump-oxygenator) before returning it to the arterial circulation. The machine does the work both of the heart (pump blood) and the lungs (supply oxygen to red blood cells).
Cardiopulmonary resuscitation:  The emergency substitution of heart and lung action to restore life to someone who appears dead. The two main components of cardiopulmonary resuscitation (CPR) are chest compression to make the heart pump and mouth-to-mouth ventilation to breath for the victim. In the event of an early heart attack, death can often be avoided if a bystander starts CPR promptly (within 5 minutes of the onset of ventricular fibrillation). When paramedics arrive, medications and/or electrical shock (cardioversion) to the heart can be administered to convert ventricular fibrillation to a normal heart rhythm. Therefore, prompt CPR and rapid paramedic response can improve the chances of survival from a heart attack.
Cardiovascular:  The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
Cardiovascular disease:  Disease affecting the heart or blood vessels. Cardiovascular diseases include arteriosclerosis, coronary artery disease, heart valve disease, arrhythmia, heart failure, hypertension, orthostatic hypotension, shock, endocarditis, diseases of the aorta and its branches, disorders of the peripheral vascular system, and congenital heart disease.
Cardiovascular syncope:  Sudden collapse into unconsciousness due to a disorder of heart rhythm in which there is a slow or absent pulse resulting in syncope (fainting) with or without convulsions. In this condition, the normal heartbeat passing from the upper chambers of the heart to the lower chambers is interrupted. This results in a condition called a "heart block." When a heart block occurs, the heart rate usually slows considerably. This can cause inadequate blood flow to the brain and result in fainting. This condition known as a Stokes Adams attack and by a baffling number of other names.
Cardiovascular system:  The circulatory system which comprises the heart and blood vessels. The system carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them. The cardiovascular system is a closed tubular system in which the blood is propelled by the heart. The system has two circuits, the pulmonary circuit and the systemic circuit. Each circuit has arterial, capillary, and venous components.
Cardioversion:  The conversion of one cardiac rhythm or electrical pattern to another, almost always from an abnormal to a normal one. This conversion can be accomplished by pharmacologic means using medications or by electrical cardioversion using a defibrillator.
Cardioverter:  Although cardioversion (the conversion of one cardiac rhythm to another) may sometimes be done with medications, a cardioverter is now synonymous with a defibrillator. Implantable defibrillators continuously monitor the heart rhythm in order to detect and correct rapid arrhythmias such as (1) ventricular tachycardia (rapid regular beating of the ventricles, the bottom chambers of the heart); and (2) ventricular fibrillation (rapid irregular beating of the ventricles). These ventricular arrhythmias impair the pumping efficiency of the heart and greatly raise the risks of fainting (syncope) and sudden cardiac arrest. They tend to develop in people with coronary artery disease and heart muscle diseases (cardiomyopathies). A defibrillator can be implanted within the body by far less invasive techniques than in the past because the devices, aside from being more technologically advanced, are smaller. (An implantable defibrillator is about the size of a minicassette). The defibrillator corrects the heart rhythm by delivering precisely calibrated and timed electrical shocks, when needed, to restore a normal heartbeat.
Carditis:  Inflammation of the heart.
Caries:  Dental cavities. Holes in the two outer layers of a tooth called the enamel and the dentin. The enamel is the outermost white hard surface and the dentin is the yellow layer just beneath enamel. Both layers serve to protect the inner living tooth tissue called the pulp, where blood vessels and nerves reside. Small cavities may not cause pain, and may be unnoticed by the patient. Larger cavities can collect food, and the inner pulp of the affected tooth can become irritated by bacterial toxins, foods that are cold, hot, sour, or sweet - causing toothache.
Carminative:  An agent that prevents or relieves flatulence (gas in the gastrointestinal tract) and, in infants, may help in the treatment of colic.
Carney complex:  A multiple neoplasia syndrome with cardiac, endocrine, cutaneous, and neural tumors together with spotty pigmentation of the skin, particularly on the face, lips, and trunk, and mucosa.
Carotene, beta:  An antioxidant, a substance that protects cells against oxidation damage which, it is thought, can lead to cancer. Beta carotene is converted, as needed, to vitamin A. Food sources of beta carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots.
Carotenemia:  Temporary yellowing of the skin due to excessive beta carotene in the diet. The offending substance, beta carotene, is an antioxidant (a substance that protects cells against oxidation damage) and is converted by the body to vitamin A. Carotenemia is most commonly seen in infants fed too many mashed carrots, or in adults taking in large quantities of carrots or carrot juice. Other common food sources of beta carotene include vegetables such as squash, sweet potatoes, spinach and other leafy green vegetables, and fruit such as cantaloupes and apricots.
Carotenoid:  One of a group of compounds that includes beta-carotene, alpha-carotene, and beta-cryptoxanthin which are converted to vitamin A and are referred to as provitamin A carotenoids. The sole known role of carotenoids is to act as a source of vitamin A in the diet. Fruits and vegetables are the main source of carotenoids in the human diet.
Carotid:  Pertaining to the carotid artery and the area near that key artery located in the front of the neck though which blood from the heart goes to the brain.
Carotid artery:  A key artery located in the front of the neck though which blood from the heart goes to the brain. There are 2 carotid arteries -- the right and left common carotid arteries -- on each side of the neck. Together, the right and left common carotid arteries provide the principal blood supply to the head and neck. The left common carotid arises directly from the aorta (the huge artery that comes from the heart). The right common carotid artery arises from the brachiocephalic artery which, in turn, comes off the aorta. Each of the two common carotid arteries divides to form external and internal carotid arteries. The external carotids are more superficial (closer to the surface) than the internal carotids (which run deep within the neck).
Carotid body:  A small "body" of tissue rich in capillaries, at the spot the carotid artery branches in the neck, containing cells that sense the oxygen and carbon dioxide levels in blood and from which messages are dispatched to the medulla (in the brain) to regulate the heart rate.
Carotid endarterectomy:  Endarterectomy (a surgical procedure designed to clean out material occluding an artery) done on the carotid artery (a major artery in the neck that supplies blood to the brain) to restore normal blood flow through it to the brain and prevent a stroke.
Carotid stenosis:  Abnormal narrowing of the carotid artery, often a preamble to a stroke.
Carpal bones:  The wrist bones. There are eight carpal bones that are arranged in two rows. The carpal bones articulate (come together to form a joint) proximally (on their near ends) with the long bones of the forearm -- the radius and, indirectly, with the ulna -- and distally (on their far ends) with the five metacarpal bones that make up the palm.
Carpal tunnel release:  A surgical procedure to relieve pressure exerted on the median nerve within the carpal tunnel (the carpal tunnel syndrome). The median nerve is pinched in the wrist as it passes through the carpal tunnel. The buildup of scar tissue inside the carpal tunnel leads to this problem. Treatment options include Vitamin B6, splinting, anti-inflammatory agents, and surgery. The surgical release is performed via a small incision using conventional surgery or a fiberoptic scope (endoscopic carpal tunnel repair). Surgical treatment is often not successful.
Carpal tunnel syndrome:  A type of compression neuropathy (nerve damage) caused by compression and irritation of the median nerve in the wrist. The nerve is compressed within the carpal tunnel, a bony canal in the palm side of the wrist that provides passage for the median nerve to the hand. The irritation of the median nerve is specifically due to pressure from the transverse carpal ligament. Carpal tunnel syndrome (CTS) can be due to trauma from repetitive work such as that of supermarket checkers, checkers in other types of stores, assembly line workers, meat packers, typists, word processors, accountants, writers, etc. Other factors predisposing to CTS include obesity, pregnancy, hypothyroidism, arthritis, and diabetes.
Cartilage:  Firm, rubbery tissue that cushions bones at joints. A more flexible kind of cartilage connects muscles with bones and makes up other parts of the body, such as the larynx and the outside parts of the ears.
Cascade:  A sequence of successive activation reactions involving enzymes (enzyme cascade) or hormones (hormone cascade) characterized by a series of amplifications of an initial stimulus. In blood coagulation, for example, each enzyme activates the next until the final product, the fibrin clot, is reached.
Casein:  The main protein found in milk and other dairy products.
Caseous:  Cheeselike. In caseous lymphadenitis, the lymph nodes turn into a soft, dry, crumbly mass resembling cheese, usually due to tuberculosis or a related infection. From caseum, the Latin word for cheese.
Cast:  (1) A protective shell of plaster and bandage molded to protect a broken or fractured limb as it heals. (2) An abnormal mass of dead cells that forms in a body cavity.
Casting, serial:  The use of successive casts to reshape deformed or spastic limbs.
Castleman disease:  A disorder of lymphoid tissue (lymphadenopathy) with massive overgrowth (hyperplasia) of lymph nodes ("swollen glands"), most commonly affecting the nodes between the lungs (in the mediastinum). There are two quite different forms of Castleman disease. One form, found in 90% cases, is a localized kind of lymphadenopathy. It usually causes no symptoms, follows an indolent (lazy) course and can be cured simply by excision (surgical removal). The far more ominous form of Castleman disease, encountered in 10% of cases, is a multicentric lymphadenopathy with progressive systemic signs and symptoms such as fever and anemia. This rapidly progressive multicentric type of Castleman disease is associated with infection by human herpesvirus 8 (HHV-8). The disease was first described by B. Castleman and colleagues in 1956.
Cat cry syndrome:  A disorder caused by the loss of part of the short (p) arm from chromosome 5. Also called the cri du chat (or cri-du-chat) syndrome. The cat cry syndrome is one of the most common human deletion syndromes with an incidence varying between 1 in 20,000 to 1 in 50,000 births. The frequency of the syndrome among profoundly retarded patients (with an IQ less than 20) is approximately 1 in 100. The syndrome was discovered in France in 1963 by a team headed by the late Jerome Lejeune. The peculiar cry of affected infants sounded to Lejeune like the meowing of a Parisian cat. The syndrome involves severe developmental and mental retardation and a characteristic constellation of congenital malformations which include microcephaly (small head), round face, hypertelorism (wide-spread eyes), micrognathia (small chin), epicanthal folds (inner eye folds), low-set ears, hypotonia (poor muscle tone), and motor and mental retardation. Although the majority of patients die in early childhood, some survive into adulthood and exhibit an IQ below 20, a loss of hypertelorism and epicanthic folds and development of a thin narrow face with prominent nasal bridge.
Cat eye syndrome:  A constitutional chromosome abnormality (one that is present at or before birth) with multiple malformations characterized by the combination of a cat-like slit of the iris of the eye (vertical coloboma) and no anal opening (anal atresia). Frequently there are also down slanting eye slits (palpebral fissures), tissue tags or pits just in front of the ears, heart malformations and kidney anomalies. There is usually normal or near-normal development with the cat eye syndrome, unlike the situation with many other constitutional chromosome abnormalities, and intelligence may be normal or near-normal in cat eye syndrome. The syndrome is due to the presence of an extra small chromosome that is smaller than chromosome 21, the smallest chromosome in humans. This extra abnormal chromosome is derived from chromosome 22. (In technical terms, this chromosome represents an inversion and duplication of chromosome band 22q11p.) The name comes from the cat-like appearance of the iris of the eye.
CAT scan:  Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures on a screen. The CAT (computerized axial tomography) scan can reveal some soft-tissue and other structures that cannot even be seen in conventional X-rays. Using the same dosage of radiation as that of an ordinary X-ray machine, an entire slice of the body can be made visible with about 100 times more clarity with the CAT scan.
Cat scratch disease:  A bacterial infection due to a cat scratch seen most often today in people with HIV. The disease characteristically presents with swollen lymph nodes (lymphadenitis), sore throat, fatigue, and fever, chills, sweats, vomiting, loss of appetite, and weight loss. There is usually a little bump (a papule) which may be pus-filled (a pustule) at the site of the scratch. Then more nodules appear on and under the skin. As the number of nodules increases, patients get sicker. In normal people the disease is self-limited and usually goes away by itself in a few weeks.
Catabolism:  The energy-burning aspect of metabolism which involves molecular breakdown (the opposite of anabolism).
Catalepsy:  The state of persistent unusual postures or facial expressions, regardless of outside stimuli, as is seen in schizophrenia and some other diseases of the nervous system.
Catalysis:  The process by which a substance speeds up a chemical reaction without being consumed or altered in the process. Substances that can accomplish this remarkable feat are termed catalysts and are of immense importance in chemistry and biology. All enzymes are catalysts that expedite the biochemical reactions necessary for life.
Catalyst:  A substance that speeds up a chemical reaction but is not consumed or altered in the process. Catalysts are of immense importance in chemistry and biology.
Cataplexy:  A debilitating medical condition in which a person suddenly feels weak and collapses at moments of strong emotion such as laughter, anger, fear or surprise. In so collapsing, people with cataplexy may injure themselves. Laughter and other emotions trigger a reflex in persons that can bring many of the muscles of the body to the point of collapse.
Cataract:  A clouding of the lens of the eye. The normally clear aspirin-sized lens of the eye starts to become cloudy. The result is much like smearing grease over the lens of a camera. It impairs normal vision.
Cataract surgery:  Removal of the clouded lens (the cataract) in its entirety by surgery, usually followed by replacement of the lens with an intraocular lens made of plastic, silicone, acrylic or other material. The operation typically takes about an hour, is done under local anesthetic only, and does not require hospitalization.
Cataract, nuclear:  A cataract that occurs in the center (the nucleus) of the lens.
Cataract, primary:  A cataract that develops independently of other diseases. A primary cataract is in contrast to a secondary cataract, one that is secondary to another disease.
Cataract, secondary:  A cataract that develops secondary to another disease or surgery. The other disease may, for example, be diabetes, glaucoma or retinal detachment. Surgery could be, for example corneal transplant. A secondary cataract is in contrast to a primary cataract, one that develops independently of any other disease.
Cataract, supranuclear:  A cataract just above the center (the nucleus) of the lens.
Catatonia:  Characterized by marked motor abnormalities including immobility (catalepsy or stupor), excessive motor activity (purposeless agitation), extreme negativism, mutism, posturing or stereotyped movements, echolalia (repeated vocalization), and/or echopraxia (repeated movements).
Catechol-O-methyltransferase (COMT):  An enzyme that catalyzes the degradation of catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. COMT is also important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. A genetic polymorphism (a common normal variant) in COMT contributes to the responses to pain and stress.
Catecholamine:  Pronounced cat·e·chol·amine. An amine derived from the amino acid tyrosine - examples include epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine - that act as hormones or neurotransmitters. There are a number of disorders involving catecholamines, including neuroblastoma, pheochromocytoma, chemodectina, the familial paraganglioma syndrome, dopamine-ß-hydroxalase deficiency, and tetrahydrobiopterin deficiency.
Cathartic:  A laxative or an emetic, i.e. anything which stimulates elimination from the body, or in a broader sense from the mind.
Cation:  In chemistry, a positively charged ion. Pronounced cat-I-on. A cation is as opposed to an anion, which is a negatively charged ion. For example table salt is expressed as Na+Cl- where Na = natrium (sodium) which is the cation and Cl = chloride which is the anion. What this means is that Chloride attracts electrons more strongly than Sodium so that in a solution where Na and Cl are floating freely, chloride has a negative charge by virtue of the fact that it herds away the electron which Na and Cl share when in a dry or crystalline form.
Cauda equina:  A bundle of spinal nerve roots that arise from the bottom end of the spinal cord. The cauda equina comprises the roots of all the spinal nerve roots below the level of the first lumbar (L1) vertebra, namely the sacral and coccygeal nerves. So named because it resembles the tail (Latin, cauda) of a horse (Latin, equus). See also Cauda equina syndrome.
Cauda equina syndrome:  Impairment of the nerves in the cauda equina, the bundle of spinal nerve roots that arise from the lower end of the spinal cord. The syndrome is characterized by dull pain in the lower back and upper buttocks and lack of feeling (analgesia) in the buttocks, genitalia and thigh, together with disturbances of bowel and bladder function.
Caudad:  Toward the feet (or, in embryology, toward the tail), as opposed to cranial. The spinal cord is caudad to the brain.
Caudal:  An anatomic term meaning 1. Pertaining to the tail or the hind part. 2. Situated in or directed toward the tail or hind part. 3. Inferior to another structure, in the sense of being below it. Caudal is also short for caudal epidural anesthesia. The terms caudal and caudad are both derived from the Latin cauda, tail.
Caudal anesthesia (Caudal epidural anesthesia):   Anesthesia produced by injection of a local anesthetic into the caudal canal, the sacral portion of the spinal canal. Caudal anesthesia is used to provide anesthesia and analgesia (pain relief) below the umbilicus. It may be the sole anesthetic or combined with general anesthesia. Also called a caudal block.
Caudate nucleus:  In each hemisphere of the brain, the most medial of the four basal ganglia, partly responsible for body movement and coordination. So named because it looks anatomically tail-like (the Latin cauda, tail).
Caul (or cowl):  a membrane, in obstetrics and cooking. In obstetrics, the caul is the amnion, one of the two fetal membranes, the other being the chorion. To be born in a caul meant to be born with the head covered by the amnion (or be born within an intact unruptured amnion). To be born in a caul was long believed to be a sign of future greatness.
Cauliflower Ear:  An acquired deformity of the external ear to which wrestlers and boxers are particularly vulnerable. The cause is damage due to trauma. When trauma causes a blood clot under the skin of the ear, the clot disrupts the connection of the skin to the ear cartilage. The cartilage has no other blood supply except the overlying skin so, if the skin is separated from the cartilage, the cartilage is deprived of nutrients and dies and the ear cartilage shrivels up to form the classic cauliflower ear. The treatment of the hematoma (the blood clot) is to drain it through an incision in the ear and apply a compressive dressing to sandwich the two sides of the skin against the cartilage. When treated promptly and aggressively, the development of cauliflower ear deformity is unlikely. Delay in diagnosis and treatment leads to more difficulty in managing this problem and may leave greater ear deformity.
Causalgia:  Intense burning pain and sensitivity to the slightest vibration or touch, usually in the hand or foot, at a site some distance removed from a wound that has healed. It is due to a distortion of sensory signals from damage to the sensory nerves which supply the area where the pain is perceived.
Cauterization:  The use of heat to destroy abnormal cells. Also called diathermy or electrodiathermy.
Caveola:  An tiny pit, depression, incupping in the surface of a cell. The name "caveola" means little cave. The plural is caveolae. Caveolae normally function to facilitate the uptake of fluid by the cell. In the process of pinocytosis, the caveolae close and pinch off to form pinosomes, little fluid-filled bubbles within the cell. Bacteria can hide in caveolae. Normally when bacteria enter cells, they go into compartments that fuse with cell structures called lysosomes in which they are destroyed. Caveolae do not fuse with lysosomes. The bacteria nestled in a caveola can thus escape extermination.
Cavernous hemangioma:  A type of hemangioma composed of blood-filled "lakes" and channels. It is typically raised and red or purplish. A cavernous hemangioma may diminish in size following trauma, bleeding or ulceration but it rarely disappears on its own. Small cavernous hemangiomas situated on the surface of the body may be removed or treated by electrocoagulation. Surgery is usually needed if a cavernous hemangioma causes increased growth of an extremity.
Cavernous sinus:  A large channel of venous blood creating a "sinus" cavity bordered by the sphenoid bone and the temporal bone of the skull. The cavernous sinus is an important structure because of its location and its contents which include the third cranial (oculomotor) nerve, the fourth cranial (trochlear) nerve, parts 1 (the ophthalmic nerve) and 2 (the maxillary nerve) of the fifth cranial (trigeminal) nerve, and the sixth cranial (abducens) nerve.
Cavernous sinus syndrome:  A cavernous sinus thrombosis is a blood clot within the cavernous sinus, a large channel of venous blood in a cavity bordered by the sphenoid bone and the temporal bone of the skull.
Cavernous sinus thrombosis:  A cavernous sinus thrombosis is a blood clot within the cavernous sinus, a large channel of venous blood in a cavity bordered by the sphenoid bone and the temporal bone of the skull. A thrombosis (clot) in this key crossroads causes the cavernous sinus syndrome which is characterized by edema (swelling) of the eyelids and the conjunctivae of the eyes and paralysis of the cranial nerves which course through the cavernous sinus.
Cavities:  Holes in the two outer layers of a tooth called the enamel and the dentin. The enamel is the outermost white hard surface and the dentin is the yellow layer just beneath enamel. Both layers serve to protect the inner living tooth tissue called the pulp, where blood vessels and nerves reside. Small cavities may not cause pain, and may be unnoticed by the patient. Larger cavities can collect food, and the inner pulp of the affected tooth can become irritated by bacterial toxins, foods that are cold, hot, sour, or sweet - causing toothache. Also referred to as caries.
Cavity, abdominal:  The cavity within the abdomen, the space between the abdominal wall and the spine. The abdominal cavity is hardly an empty space. It contains a number of crucial organs including the lower part of the esophagus, the stomach, small intestine, colon, rectum, liver, gallbladder, pancreas, spleen, kidneys, and bladder.
CBC:  A commonly used abbreviation in medicine that stands for complete blood count, a set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute. The values generally included are the following:

* White blood cell count (WBC). The number of white blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4,300 and 10,800 cells per cubic millimeter (cmm). This can also be referred to as the leukocyte count and can be expressed in international units as 4.3 - 10.8 x 1000 cells per liter.

* Automated white cell differential. A machine generated percentage of the different types of white blood cells, usually split into granulocytes, lymphocytes, monocytes, eosinophils, and basophils.

* Red cell count (RBC). The number of red blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4.2 - 5.9 million cells/cmm. This can also be referred to as the erythrocyte count and can be expressed in international units as 4.2 - 5.9 x 1,000,000 cells per liter.

* Hemoglobin (Hb). The amount of hemoglobin in a volume of blood. Hemoglobin is the protein molecule within red blood cells that carries oxygen and gives blood its red color. Normal range for hemoglobin is different between the sexes and is approximately 13 - 18 grams per deciliter for men and 12 - 16 for women (international units 8.1 - 11.2 millimoles/liter for men, 7.4 - 9.9 for women).

* Hematocrit (Hct). The ratio of the volume of red cells to the volume of whole blood. Normal range for hematocrit is different between the sexes and is approximately 45 - 52% for men and 37 - 48% for women.

* Mean cell volume (MCV). The average volume of a red cell. This is a calculated value derived from the hematocrit and red cell count. Normal range is 86 - 98 femtoliters.

* Mean cell hemoglobin (MCH). The average amount of hemoglobin in the average red cell. This is a calculated value derived from the measurement of hemoglobin and the red cell count. Normal range is 27 - 32 picograms.

* Mean cell hemoglobin concentration (MCHC). The average concentration of hemoglobin in a given volume of red cells. This is a calculated volume derived from the hemoglobin measurement and the hematocrit. Normal range is 32 - 36%.

* Red cell distribution width (RDW). A measurement of the variability of red cell size. Higher numbers indicate greater variation in size. Normal range is 11 - 15.

* Platelet count. The number of platelets in a volume blood. Platelets are not complete cells, but actually fragments of cytoplasm from a cell found in the bone marrow called a megakaryocyte. Platelets play a vital role in blood clotting. Normal range varies slightly between laboratories but is in the range of 150,000 - 400,000/ cmm (150 - 400 x 109/liter).

CCD (Central core disease of muscle):  One of the conditions that produces 'floppy baby' syndrome. CCD causes hypotonia (floppiness) in the newborn baby, slowly progressive muscle weakness, and muscle cramps after exercise. Muscle biopsy shows a key diagnostic finding (absent mitochondria in the center of many type I muscle fibers). CCD is inherited as a dominant trait.
CCD (cleidocranial dysostosis):  A genetic disorder of bone development characterized by: 1. Absent or incompletely formed collar bones (cleido refers to the clavicles, the collar bones) The child with this disorder can bring its shoulders together or nearly so. 2. Typical cranial and facial abnormalities with square skull, late closure of the sutures of the skull, late closure of the fontanels (the soft spots), low nasal bridge, delayed eruption of the teeth, abnormal permanent teeth, etc. The disorder is transmitted in an autosomal dominant manner.
CCHF (Crimean-Congo hemorrhagic fever):  A viral disease characterized by hemorrhage (bleeding) and fever. It is a severe disease with a high mortality (death) rate. The geographical distribution of the virus, like that of the tick that carries it, is widespread. CCHF has been found in Africa, Asia, the Middle East and Eastern Europe. The CCHF virus infects a wide range of domestic and wild animals that serve as reservoirs for the virus. Ticks carry the virus from animal to animal and from animal to human. The most important source for acquisition of the virus by ticks is infected small vertebrate animals on which the ticks feed.
CD4:  A large glycoprotein molecule found on the surface of T lymphocytes that serves as the receptor for HIV. The CD4 gene is on chromosome 12 in region 12pter-p12. CD4 is also called T4.
CD8 + T Cell (Cytotoxic T-lymphocyte):  A T cell (cell "soldiers" which search out and destroy the targeted invaders; The "T" stands for "thymus" -- the organ in which these cells mature. As opposed to B cells which mature in the bone marrow.) that is antigen-specific and is able to search out and kill specific types of virus-infected cells. When cytotoxic T-lymphocytes (CTLs) find cells carrying the viral peptide they are looking for, they induce these cells to secrete proteins that attract nearby macrophages (a type of white blood cells). These macrophages then surround and destroy the infected cells. CTLs are important in the body's response to viruses and cancer. CTLs express the CD8 transmembrane glycoprotein and are therefore also known as CD8 + T cells or CT cells.
CEA (Carcinoembryonic antigen):  a protein found in many types of cells but associated with tumors and the developing fetus. CEA is tested in blood. The normal range is <2.5 ng/ml in an adult non-smoker and <5.0 ng/ml in a smoker. Benign conditions that can increase CEA include smoking, infection, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, and some benign tumors (in the same organs which have cancers with increased CEA). Benign disease does not usually cause a CEA increase over 10 ng/ml. The main use of CEA is as a tumor marker, especially with intestinal cancer. The most common cancers that elevate CEA are in the colon and rectum. Others: cancer of the pancreas, stomach, breast, lung, and certain types of thyroid and ovarian cancer. Levels over 20 ng/ml before therapy are associated with cancer which has already metastasized (spread).
Celiac disease (Celiac Sprue):  A disorder resulting from an immune reaction to gluten, a protein found in wheat and related grains, and present in many foods. Celiac disease causes impaired absorption and digestion of nutrients through the small intestine. Symptoms include frequent diarrhea and weight loss. A skin condition dermatitis herpetiformis can be associated with celiac disease. The most accurate test for celiac disease is a biopsy of the involved small bowel. Treatment is to avoid gluten in the diet. Medications are used for stubborn cases of celiac disease.
Cell:  The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane.
Cell cloning:  The process of producing a group of cells (clones), all genetically identical, from a single ancestral cell.
Cell fusion:  The melding of two or more cells into one cell called a heterokaryon. A heterokaryon may reproduce itself for at least several generations.
Cell therapy:  Treatment with cells. A technology that relies on replacing diseased or dysfunctional cells with healthy, functioning ones. Whole blood transfusions, packed red cell transfusions, platelet transfusions, bone marrow transplants, and organ transplants are all forms of cell therapy.
Cellulite:  Popular term for deposits of fat that have a cottage cheese-like or puckered texture. Medically, cellulite is not considered abnormal.
Cellulitis:  An acute spreading bacterial infection below the surface of the skin characterized by redness (erythema), warmth, swelling, and pain and may also cause fever, chills, and "swollen glands" (enlarged lymph nodes).
Celsus:  (1st century A.D.) Aulus (Aurelius) Cornelius Celsus. Roman encyclopedist whose only surviving work, De Medicina, was rediscovered and printed early in the Renaissance and became influential. His four classical signs of inflammation -- calor, dolor, rubor, and tumor (heat, pain, redness, and swelling) -- are still useful today.
Cemento-ossifying Fibroma:  A hard fibrous lesion that continues to grow, sometimes to very large size, unless treated, most frequently seen in the jaw or mouth, sometimes in connection with a fracture or another type of injury. Treatment is by surgical.
Centenarian:  Someone who is 100 or more years old. Someone 110 years old and over (no upper limit) may also be referred to as a supercentenarian. See also: Age by decade.
Centigrade:  Thermometer scale in which the freezing point of water is 0°C and the boiling point of water at sea level is 100°C. The Centigrade scale is used around most of the world to indicate the temperature on a thermometer while the Fahrenheit scale is still in use in the US. This requires conversion from Centigrade (°C) to Fahrenheit (°F), and vice versa. One degree °C = (5/9)(°F - 32). One degree °F = (9/5)(°C) + 32.
Central auditory processing disorder:  A condition in which there is an inability to differentiate, recognize or understand sounds while both the hearing and intelligence are normal.
Central catheter:  A catheter (a tube) that is passed through a vein to end up in the thoracic (chest) portion of the vena cava (the large vein returning blood to the heart) or in the right atrium of the heart.
Central core disease of muscle:  One of the conditions that produces 'floppy baby' syndrome. CCD causes hypotonia (floppiness) in the newborn baby, slowly progressive muscle weakness, and muscle cramps after exercise. Muscle biopsy shows a key diagnostic finding (absent mitochondria in the center of many type I muscle fibers).
Central nervous system (CNS):  The central nervous system is that part of the nervous system that consists of the brain and spinal cord. The central nervous system (CNS) is one of the two major divisions of the nervous system. The other is the peripheral nervous system (PNS) which is outside the brain and spinal cord.
Central retinal artery:  The blood vessel that carries blood into the eye and supplies nutrition to the retina.
Central retinal vein:  The blood vessel that carries blood away from the retina of the eye.
Central venous catheter:  A catheter (tube) that is passed through a vein to end up in the thoracic (chest) portion of the vena cava (the large vein returning blood to the heart) or in the right atrium of the heart.
Central vision:  Straight-ahead vision. Central vision is the work of the macula, a small area in the center of the retina that contains a rich collection of cones. (The retina is made up of two types of cells, the cones and the rods. Millions of cones are packed into the macula. The cones are nerve cells sensitive to light, fine detail, and color.) Central vision permits a person to read, drive, and perform other activities that require fine, sharp, straight-ahead vision as opposed to peripheral vision.
Centrencephalic seizure ("grand mal seizure"):   A form of epilepsy characterized by tonic-clonic seizures. involving two phases -- the tonic phase in which the body becomes rigid, and clonic phase in which there is uncontrolled jerking. Tonic-clonic seizures may or may not be preceded by an aura, and are often followed by headache, confusion, and sleep. They may last for mere seconds, or continue for several minutes. If a tonic-clonic seizure does not resolve or if such seizures follow each other in rapid succession, seek emergency help. The person could be in a life-threatening state known as status epilepticus (unremitting seizures). Treatment is with antiseizure medications.
Cerebral cortex:  A thin mantle of gray matter about the size of a formal dinner napkin covering the surface of each cerebral hemisphere. The cerebral cortex is crumpled and folded, forming numerous convolutions (gyri) and crevices (sulci). It is made up of six layers of nerve cells and the nerve pathways that connect them. The cerebral cortex is responsible for the processes of thought, perception and memory and serves as the seat of advanced motor function, social abilities, language, and problem solving
Cerebral edema:  Accumulation of excessive fluid in the substance of the brain. The brain is especially susceptible to injury from edema, because it is located within a confined space and cannot expand.
Cerebral fornix:  An arching fibrous band in the brain connecting the two lobes of the cerebrum. (The cerebrum is the largest part of the brain and consists of two hemispheres separated by a deep longitudinal fissure). Each fornix -- there are two -- in the brain is an arched tract of nerves.
Cerebral hemispheres:  The two halves of the cerebrum, the largest part of the brain.
Cerebral herniation:  The abnormal protrusion of brain tissue through an opening when there is increased intracranial pressure (when the brain is under increased pressure). The increased pressure may be due to a number of causes including inflammation of the brain (as in meningitis), a tumor, hemorrhage, and edema (swelling of the brain). The tonsils of the cerebellum, for example, may be forced from their normal position (within the posterior fossa of the skull) through the foramen magnum into the vertebral canal. This is usually fatal.
Cerebral palsy:  An abnormality of motor function (the ability to move and control movements) that is acquired at an early age, usually less than a year of age, and is due to a brain lesion that is non-progressive. Cerebral palsy (CP) is frequently the result of abnormalities that occur in utero, while the fetus is developing inside the mother's womb. Such abnormalities may include accidents of brain development, genetic disorders, stroke due to abnormal blood vessels or blood clots, or infection of the brain. In rare instances, obstetrical accidents during particularly difficult deliveries can cause brain damage and result in CP. A common cause of cerebral palsy in difficult deliveries is susatined under-oxygenization of the brain due to compression of the umbilical cord or choking of the newborn by an umbilical cord that is wrapped around the newborn's neck.
Cerebral ventricle:  One of a system of four communicating cavities within the brain that are continuous with the central canal of the spinal cord. The four ventricles consist of the two lateral ventricles, the third ventricle and the fourth ventricle.
Cerebritis:  Inflammation of the brain.
Cerebrohepatorenal syndrome:  A genetic disorder, which is also called the Zellweger syndrome, characterized by the reduction or absence of peroxisomes (cell structures that rid the body of toxic substances) in the cells of the liver, kidneys, and brain. Zellweger syndrome is one of a group of disorders called the leukodystrophies, all of which affect the myelin sheath, the fatty covering which acts as an insulator on nerve fibers in the brain.
Cerebrospinal fluid:  The watery fluid that fills the spaces in and around the brain and spinal cord. Also called CSF.
Cerebrovascular:  Pertaining to the blood vessels and, especially, the arteries that supply the brain. As in cerebrovascular accident or cerebrovascular disease.
Cerebrovascular accident:  The sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A CVA is also referred to as a stroke. Symptoms of a stroke depend on the area of the brain affected. The most common symptom is weakness or paralysis of one side of the body with partial or complete loss of voluntary movement or sensation in a leg or arm. There can be speech problems and weak face muscles, causing drooling. Numbness or tingling is very common. A stroke involving the base of the brain can affect balance, vision, swallowing, breathing and even unconsciousness. A stroke is a medical emergency. Anyone suspected of having a stroke should be taken immediately to a medical facility for diagnosis and treatment. The causes of stroke: An artery to the brain may be blocked by a clot (thrombosis) which typically occurs in a blood vessel that has previously been narrowed due to atherosclerosis ("hardening of the artery"). When a blood clot or a piece of an atherosclerotic plaque (a cholesterol and calcium deposit on the wall of the artery) breaks loose, it can travel through the circulation and lodge in an artery of the brain, plugging it up and stopping the flow of blood; this is referred to as an embolic stroke. A blood clot can form in a chamber of the heart when the heart beats irregularly, as in atrial fibrillation; such clots usually stay attached to the inner lining of the heart but they may break off, travel through the blood stream, form a plug (embolus) in a brain artery and cause a stroke. A cerebral hemorrhage (bleeding in the brain), as from an aneurysm (a widening and weakening) of a blood vessel in the brain, also causes stroke.
Cerebrovascular ferrocalcinosis:  A condition, first described in 1930 by T. Fahr and therefore called Fahr syndrome, that is a genetic (inherited) neurological disorder characterized by abnormal deposits of calcium in certain of areas of the brain (including the basal ganglia and the cerebral cortex). Symptoms may include motor function deterioration, dementia, mental retardation, spastic paralysis, dysarthria (poorly articulated speech), spasticity (stiffness of the limbs), ocular (eye) problems, and athetosis (involuntary, writhing movements) and also features of Parkinson's disease.
Cerebrum:  The largest part of the brain. It is divided into two hemispheres, or halves. The cerebral contex is thought to be the part of the brain most responsible for reasoning, thought, and memory. The word "cerebrum" is the Latin word for "brain."
Ceruloplasmin deficiency:  Lack of the protein ceruloplasmin from the blood and accumulation of iron in the pancreas, liver and brain, causing diabetes and progressive nervous system degeneration with the tremors and gait abnormalities characteristic of Parkinson's disease. Ceruloplasmin deficiency is a genetic condition, also known as aceruloplasminemia. Ceruloplasmin normally removes iron from cells. The absence of ceruloplasmin leads to the abnormal deposition of iron in cells, including those of the pancreas, liver, retina and the basal ganglia region of the brain. The iron deposition damages these tissues and leads to the clinical features of the disease which usually appear between 30 and 50 years of age. Aggressive treatment with deferoxamine, a chelating agent that takes up iron, may halt the progression of these complications.
Cervical:  Having to do with any kind of neck including the neck on which the head is perched and the neck of the uterus. The word "cervix" in Latin means "neck". That is why cervical vertebrae and cervical cancer involve quite disparate parts of the anatomy joined only by the meaning of the word "cervix."
Cervical cancer:  Cancer of the entrance to the womb (uterus). The cervix is the lower, narrow part of the uterus (womb).
Cervical cap:  A soft rubber cup with a round rim designed to fit snugly around the cervix and act as a barrier contraceptive device. A spermicide is applied to the cap before insertion to kill sperm. A cervical cap is basically a small snug diaphragm and, like a diaphragm, a cervical cap must be sized by a health professional and is available by prescription only. A cervical cap protects against conception for 48 hours and for multiple acts of intercourse within that time. Wearing a cervical cap for more than 48 hours is not recommended because of the risk of toxic shock syndrome (TSS), a rare but potentially fatal condition. Symptoms of TSS include sudden fever, an stomach upset, a sunburn-like rash, and a drop in blood pressure.
Cervical cerclage:  The surgical placement of a purse-string suture around an incompetent cervix, one that is abnormally liable to dilate, in order to prevent premature onset of labor and a miscarriage. The suture material must be removed prior to delivery.
Cervical disc:  A disk shaped piece of specialized tissue that separates the vertebral bones of the spinal column in the neck. The center of the disc, which is called the nucleus, is soft, springy and receives the shock of standing, walking, running, etc. The outer ring of the disc, which is called the annulus (Latin for ring), provides structure and strength to the disc. The annulus consists of a complex series of interwoven layers of fibrous tissue that hold the nucleus in place.
Cervical dysplasia:  Changes from normal in the cells lining the cervix of the uterus. Cervical dysplasia involves a sequence of cellular changes from mild to severe that are not yet cancerous but constitute the prelude to cancer of the cervix. The diagnosis of cervical dysplasia is made from the PAP smear.
Cervical intraepithelial neoplasia:  A general term for the growth of abnormal cells on the surface of the cervix. Numbers from 1 to 3 may be used to describe how much of the cervix contains abnormal cells. Also called CIN.
Cervical kyphosis, postmenopausal:  An outward curvature (kyphosis) of the cervical vertebrae (the bones of the neck), creating a hump at the back of the neck. This condition, once thought to be a characteristic deformity of older women, was called a dowager's hump. A dowager was a woman of high social rank whose husband was dead but who had a title (such as duchess) and property because of her marriage to him. Postmenopausal cervical kyphosis is due to osteoporotic changes in the cervical spine. It may affect men or women. Like most osteoporotic changes, the condition is often preventable.
Cervical rib:  A supernumerary (extra) rib which arises from the seventh cervical vertebra. It is located above the normal first rib. A cervical rib is present in only about 1 in 200 (0.5%) of people. It may cause nerve and artery problems. There are normally 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the vertebrae) in the back. The 12 normal pairs of ribs consist of: True ribs: The first seven ribs attach to the sternum (the breast bone) in the front and are known as true (or sternal) ribs. False ribs: The lower five ribs do not directly connect to the sternum and are known as false ribs. The presence of a cervical rib means the individual has 13 ribs: 1 cervical rib + 7 true ribs + 5 false ribs = 13 ribs.
Cervical vertebra, first:  The first cervical (neck) vertebra is called the atlas. It supports the head. The atlas bone is named for the Greek god Atlas who was condemned to support the earth and its heavens on his shoulders. (Because the god Atlas often adorned maps, a compilation of maps came to be known as an atlas).
Cervical vertebra, second:  The second cervical vertebra is called the axis. It is so-named because the uppermost cervical vertebra (called the atlas) rotates about the odontoid process of the second cervical vertebra. The joint between the axis and atlas is a pivot type of joint. It allows the head turn. The Latin word "axis" means axle or pole. The axis bone serves as the axle about which the atlas (and the head) turn.
Cervical vertebrae:  The cervical (neck) vertebrae are the upper 7 vertebrae in the spinal column (the vertebral column). They are designated C1 through C7 from the top down. C1 is called the atlas. It supports the head and is named for the Greek god Atlas who was condemned to support the earth and its heavens on his shoulders. (Because the god Atlas often adorned maps, a compilation of maps came to be known as an atlas). C2 is called the axis because the atlas rotates about the odontoid process of C2. The joint between the atlas and axis is a pivot that allows the head to turn.
Cervicectomy:  Surgical removal of the cervix, the lower portion of the uterus that protrudes into the vagina. Cervicectomy is also called trachelectomy.
Cervicitis:  Inflammation of the cervix.
Cervix:  The cervix is the lower, narrow part of the uterus (womb). The uterus, a hollow, pear-shaped organ, is located in a woman's lower abdomen, between the bladder and the rectum. The cervix forms a canal that opens into the vagina, which leads to the outside of the body.
Cervix, incompetent:  A cervix that is abnormally liable to dilate and so is not competent to hold the fetus and keep it from being spontaneously aborted (miscarried).
Cesarian section:  The obstetrical procedure is often spelled this way in the U.S. with just an "e" although the Roman emperor remains Caesar in America with an "ae". Also referred to as a C-section. No matter what, it is a procedure in which a baby, rather than being born vaginally, is surgically extracted (removed) from the uterus. As the name "Cesarian" suggests, this is not exactly a new procedure. It was done in ancient civilizations upon the death of a pregnant woman who was near full term in order to salvage the baby. Julius Caesar (or one of his predecessors) was born by this procedure.
Chagas disease:  An infection caused by the parasite Trypanosoma cruzi. Also called American trypanosomiasis. Transmitted by reduviid bugs, or kissing bugs, that live in cracks and holes of substandard housing primarily found in South and Central America. These insects become infected after biting an animal or person who already has Chagas disease. Infection is spread to humans when an infected bug deposits feces on a person's skin, usually while the person is sleeping at night. The person often accidently rubs the feces into the bite wound, an open cut, the eyes, or mouth. Infected mothers can pass infection to their baby during pregnancy, at delivery, or while breastfeeding.
Chalazion:  A cyst of the little glands in the eyelids that make a lubricant which they discharge through tiny openings in the edges of the lids. The lubricant is a fatty substance called sebum characteristic of sebaceous glands. These glands are called the Meibomian glands. Inflammation of them is termed meibomianitis or, alternatively, meibomitis. Chronic inflammation of the Meibomian glands leads to Meibomian cysts or chalazions. The word "chalazion" is Greek for small pimple (and little hail). Like a pimple, a chalazion is an inflamed swelling. But instead of being on the skin, a chalazion is in the margin of the eyelid. The Meibomian glands are named for a 17th-century German anatomist Heinrich Meibom (who must have had good eyes to see these minute structures). They are also known as the palpebral glands, tarsal glands, or tarsoconjunctival glands.
Chamomile:  An herb often used in the form of a tea as a sedative or soporific (sleep inducer).
Chancre:  The classic painless ulcer of syphilis. The chancre forms in the first (primary) stage of syphilis. It is highly contagious and can last 1-5 weeks. The disease can be transmitted from contact with the ulcer, which is teeming with spirochetes. If the ulcer is outside of the vagina or on the scrotum of the male, the use of condoms may not help in preventing transmission of the disease. Likewise, if the ulcer is in the mouth, merely kissing the infected individual can spread syphilis.
Chancroid:  A sexually transmitted infection (STI) caused by the bacterium Haemophilus ducreyi. Periodic outbreaks of chancroid have occurred in the US, usually in minority populations in the inner cities. This disease is common in sub-Saharan Africa among men who have frequent contact with prostitutes. The infection begins with the appearance of painful open sores on the genitals, sometimes accompanied by swollen, tender lymph nodes in the groin. These symptoms occur within a week after exposure. Symptoms in women are often less noticeable and may be limited to painful urination or defecation, painful intercourse, rectal bleeding, or vaginal discharge.
Chandipura virus:  A virus that causes fever, symptoms similar to those of flu, and acute encephalitis (inflammation of the brain). Chandipura virus was first isolated in 1965 in a village in Maharashtra State, India. Since then, the virus has been reported in adjoining states in central India. The likely vector (carrier) of the virus is the female phlebotomine sandfly. This virus should be considered as an important emerging pathogen.
Channelopathy:  A disease involving dysfunction of an ion channel. Channelopathies are known that involve the ion channels for potassium, sodium, chloride and calcium. There are also channelopathies involving the acetylcholine receptor, the glycine receptor, and other receptors. Each channelopathy can play a role in a number of different diseases. For example, the calcium channelopathies include familial hemiplegic migraine, malignant hyperthermia (a rare but often fatal genetic condition during anesthesia), episodic ataxia type 2, spinocerebellar ataxia type 6, hypokalemic periodic paralysis type I, central core disease (a cause of the floppy baby syndrome), congenital night blindness and stationary night blindness.
Chaperone:  Any protein that is required for the proper folding or assembly of another protein or protein complex without being a component of the final structure.
Charbon:  Known also as anthrax, charbon is a serious bacterial infection. It is not primarily a human disease but rather an infection of animals. Cattle, sheep, horses, mules, and some wild animals are highly susceptible. Humans (and swine) are generally resistant to anthrax. Anthrax can take different forms. With the lung form of the disease. People inhale the anthrax spores and, if untreated, are likely to die. An intestinal form is caused by eating meat contaminated with anthrax. But most human anthrax comes from skin contact with animal products. Cutaneous (skin) anthrax was once well known among people who handled infected animals, like farmers, woolsorters, tanners, brushmakers and carpetmakers in the days when the brushes and carpets were animal products. The hallmark of skin anthrax is a carbuncle, a cluster of boils, that ulcerates in an ugly way. Typically this lesion has a hard black center surrounded by bright red inflammation. This accounts for its name, "anthrax", the Greek word for "coal". "Charbon" in French means "coal."
Charcot-Marie-Tooth disease:  A genetic disease of nerves characterized by progressively debilitating muscle weakness, particularly of the limbs. The foremost feature is marked wasting of the distal extremities, particularly the peroneal muscle groups in the calves, resulting in "stork legs." The disease usually weakens the legs before the arms.
Charcot-Wilbrand syndrome:  Loss of dreaming after a stroke. In more technical terms the syndrome is characterized by visual agnosia (inability to make sense of what one can see) and the inability to revisualise images. Named for the French founder of modern neurology Jean-Martin Charcot (1825-1893) and the German neuro-ophthalmologist Hermann Wilbrand.
Charley horse:  A cramp in a muscle in the leg, usually caused by a strain or injury. A charley horse can last anywhere from a few seconds to a quarter of an hour, and occasionally longer. It is not uncommon for one to recur repeatedly before it finally goes away. The term "charley horse" is generally believed to be American baseball slang. One story involves Charley (Old Hoss) Radbourn (1853-1897) who was rounding third base when he developed a cramp in his leg. As he limped home, a player asked, "What's the matter, Charley Hoss?" "My leg is tied up in knots." Charley replied. From then on, when a baseball player's leg cramped, he called it a charley horse.
Chasing the dragon:  A bit of slang related to the practice of heroin use involving heating heroin and then inhaling it. Some heroin users have gone to this practice because they believe erroneously that it will protect them against contracting HIV and other diseases associated with injecting heroin. "Chasing the dragon" carries a risk of untreatable brain damage with death occurring in about 20% of cases. Abnormalities occur in the cerebellum, the area of the brain that controls coordination of movement. Some patients develop symptoms of a rare brain disorder, progressive spongiform leukoencephalopathy in which fluid-filled spaces cover the brain's white matter and there is loss of coordination, slowed movements and difficulty moving and talking.
CHD (Congenital heart disease):  a malformation of the heart or the large blood vessels near the heart. The term "congenital" speaks only to time, not to causation; it means "born with" or "present at birth." Congenital heart disease is the most frequent form of major birth defects in newborns affecting close to 1% of newborn babies (8 per 1,000).
Checkpoint:  A surveillance system responsible for monitoring the proper completion of an event within a cell. Cells contain a number of such systems. When a checkpoint system detects the failure of an event, it signals and calls for the inhibition of events downstream to the failure. These surveillance systems are termed checkpoints because they represent stages in the cell cycle at which the cell checks to be certain it is okay to proceed. Checkpoints control the order and timing of cell cycle transitions and ensure that critical events, such as DNA replication and chromosome segregation, are completed with high fidelity.
Cheilitis:  Inflammation of the lips or of a lip. Cheilitis can also be spelled chilitis. Angular cheilitis is inflammation and fissuring radiating from the commissures (angles) of the mouth secondary to predisposing factors such as nutritional deficiencies, atopic dermatitis, or Candida albicans (yeast) infection. Also called angular stomatitis or commissural cheilitis.
Cheiroarthropathy:  A syndrome of limited joint mobility that occurs in patients with diabetes. Cheiroarthropathy is characterized by thickening of the skin resulting in contracture of the fingers. Cheiroarthropathy causes such limited motion of the fingers that the affected individual is unable to extend the fingers to fully flatten the hand. Typically both hands are affected by cheiroarthropathy. Cheiroarthropathy has been reported in over half of patients with insulin-dependent diabetes and approximately three quarters of those with noninsulin-dependent diabetes. Cheiroarthropathy occurs more frequently in those with a longer history of diabetes. Treatment of cheiroarthropathy includes pain reliever and/or antiinflammation medicines, stretching exercises, and tight control of the blood sugar level.
Chemical menopause:  a type of "induced menopause", menopause induced by an unusual event, such as may also occur when the ovaries are damaged by radiation or when the ovaries are surgically removed (by bilateral oophorectomy). Induced menopause, chemical menopause included, is distinct from natural menopause which occurs when the ovaries naturally decrease their production of the sex hormones estrogen and progesterone.
Chemobrain:  Cognitive dysfunction associated with chemotherapy. It is thought that chemotherapy may cause memory loss, attention loss, and other problems that make it difficult for patients to think clearly. Also known as chemo-brain, chemo-fog, and chemotherapy-related cognitive dysfunction.
Chemoembolization:  A procedure in which the blood supply to a tumor is blocked and anticancer drugs are administered directly into the tumor, permitting a much higher concentration of drugs to be in contact with the tumor for a longer period of time, while depriving the tumor of oxygen and nutrients. The procedure is used to treat cancer originating in the liver (primary liver cancer) as well as cancer that has metastasized (spread) to the liver from another area.
Chemokine:  One of a large group of proteins that act as lures and were first found attracting white blood cells. The chemokines are involved in a wide variety of processes including acute and chronic types of inflammation, infectious diseases, and cancer. Chemokines may lure cancer cells and help determine the sites to which cancer cells spread by metastasis. The first chemokine to be identified was interleukin-8 (IL-8).
Chemokine receptor:  A molecule that receives a chemokine and a chemokine dock.
Chemokinesis:  The response of a cell to a chemical that causes the cell to make some kind of change in its movement by speeding it up, slowing it down or changing its direction. The molecules that achieve these results are called chemokines.
Chemoprevention:  The use of natural or laboratory-made substances to prevent a disease such as cancer. The regular use of aspirin is known to reduce the risk of the polyps from which colorectal cancer arises. This is an instance of chemoprevention. The term chemoprevention was coined to parallel the term chemotherapy. Chemoprevention prevents and chemotherapy treats. Chemoprevention is also called chemoprophylaxis.
Chemoradiotherapy:  The combination of simultaneous chemotherapy and radiation therapy. Chemoradiotherapy before surgery has been found to reduce the risk of local recurrence of rectal cancer.
Chemosense:  The chemical sensing system. The sense of smell is part of our chemical sensing system, or the chemosenses.
Chemosensory:  Pertaining to the sensing of chemicals, as by olfaction (the sense of smell). Diabetes and Parkinson's disease are among the diseases accompanied or signaled by chemosensory problems such as smell disorders.
Chemosis:  Swelling around the iris (the colored circle that surrounds the pupil) due to edema (swelling) of the bulbar conjunctiva (the clear membrane that coats the outer surface of the eye).
Chemotherapy:  1. In the original sense, a chemical that binds to and specifically kills microbes or tumor cells. The term chemotherapy was coined in this regard by Paul Ehrlich (1854-1915). 2. In oncology, drug therapy for cancer. Also called "chemo" for short. Most cancer chemotherapeutic drugs are given IV (into a vein) or IM (into muscle). Some anticancer agents are taken orally (by mouth). Chemotherapy is usually systemic treatment, meaning that the drugs flow through the bloodstream to nearly every part of the body.
Chemotherapy, adjuvant:  Chemotherapy (drug therapy) that is given after surgery to remove a cancer. The idea underpinning adjuvant chemotherapy is that the toxic drugs are more effective after the main tumor has been removed and any cancer that remains is in very small amounts (microscopic metastases). For example, in a case of colon cancer, the primary tumor would first be resected (removed) from the colon. Then the adjuvant chemotherapy would then be carried out. The chemotherapy drugs might be given intravenously and instilled directly into the abdomen.
Chen, Zhong Wei:  (1929-2004) Chinese surgeon considered the "father of replantation." Dr. Chen was the first to reattach a severed hand with success which he did in 1963.
Cherubism:  A genetic disorder of childhood that leads to prominence of the lower face and an appearance reminiscent of the cherubs portrayed in Renaissance art. Cherubism is due to a problem in bone formation that is largely limited to the upper and lower jaws (the maxilla and mandible) with loss of bone in the jaws and its replacement by excessive amounts of fibrous tissue. These abnormalities often resolve after puberty. Cherubism is inherited as an autosomal dominant condition. Most boys and girls with it have a parent who had cherubism, while the few children with cherubism without a family history are thought to have a new mutation (a newly arisen gene) for cherubism but can transmit it to their children.
Chest:  The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum.
Chest X-ray:  Commonly used to detect abnormalities in the lungs, but can also detect abnormalities in the heart, aorta, and the bones of the thoracic area.
CHF (Congestive heart failure):  Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.
Chickenpox:  A highly infectious viral disease also known medically as varicella -- in many countries, this disease is always called "varicella" -- that causes a blister-like rash, itching, fatigue and fever. The rash crops up first on the face and trunk and can spread over the entire body resulting in 250 to 500 itchy blisters. Chickenpox is highly infectious. The virus spreads from person to person by direct contact or through the air by coughing or sneezing. It takes from 10-21 days after contact with an infected person for someone to develop chickenpox. People with chickenpox are contagious a day or two before the rash appears and until all blisters have formed scabs. In children, chickenpox most commonly causes an illness that lasts about 5-10 days. Children usually miss 5 or 6 days of school or childcare due to their chickenpox. Their symptoms may include high fever, severe itching, an uncomfortable rash, dehydration, and headache. About 1 child in 10 has a complication from chickenpox -- infected skin lesions, other infections, dehydration from vomiting or diarrhea, exacerbation (worsening) of asthma and pneumonia -- that is serious enough to warrant a visit to the doctor. Certain people are especially likely to have a serious illness from chickenpox. These at-risk groups include infants, adolescents, and adults and people with weak immune systems from either illnesses or from medications such long-term steroids or chemotherapy. Chickenpox has nothing at all to do with chicken. The name was meant to distinguish this "weak" form of the pox from smallpox. "Chicken" is used here, as in "chickenhearted," to mean weak or timid. The "pox" of chickenpox is no major matter unless it becomes infected (through scratching) or occurs in an immunodeficient person. However, there can be very major problems from chickenpox including pneumonia and encephalitis and reactivation of the same herpes virus is responsible for shingles (zoster). Chickenpox is responsible for more deaths than measles (rubeola), mumps, whooping cough (pertussis) and H. flu (Haemophilus influenzae type B) meningitis combined. Contrary to what many people believe, chickenpox is by no means a mild disease. A healthy person can die from the disease. From 1990 to 1994, before there was a vaccine available, there were about 50 chickenpox deaths in children and 50 chickenpox deaths in adults every year in the US. Most of these persons were healthy or did not have a medical illness such as cancer that placed them at higher risk of getting severe chickenpox. Most of the healthy adults who die from chickenpox contract the disease from their unvaccinated children.
Chickenpox immunization:  Immunization designed to prevent or lessen the severity of the common disease known as chickenpox. The vaccination currently involves only one shot, given at about one year of age. If an older person has not had chickenpox, the shot may be given at any time. Bearing in mind that without vaccine there are about 100 deaths from complications of chicken pox per year in a population of about 300 million and keeping in mind the side-effects and dangers of vaccines, and the fact that chicken pox itself gives immunity to further illess from this virus, parents must choose to vaccinate or not.
Chickenpox rash:  Chickenpox is characterized by a rash, often the first sign of the disease. The rash of chickenpox develops in crops with raised red spots arriving first, progressing to blisters that burst, creating open sores, before crusting over. This process usually starts on the scalp, then the trunk (its area of greatest concentration), and finally the arms and legs. Any area of skin that is irritated (by diaper rash, eczema, sunburn, etc.) is likely to be hard hit by the rash. The rash is typically very itchy (pruritic).
Chikungunya:  An urban disease resembling dengue, seen mainly in Africa, the Indian subcontinent, and Southeast Asia, caused by an arbovirus transmitted by Aedes mosquitoes. The most prominent frequent feature is severe arthritis. Chikungunya fever was first described in epidemic form in East Africa in 1952-1953. The virus is arthropod-borne (it is therefore an arbovirus) and belongs to the family Togaviridae, genus Alphavirus. Human infections are acquired by the bite of infected Aedes aegypti mosquitoes, and epidemics are sustained by human-mosquito-human transmission.
Chilblain:  A cold injury which, while painful, causes little or no permanent impairment. It appears as red, swollen skin which is tender, hot to the touch, and may itch. This can worsen to an aching, prickly ("pins and needles") sensation, and then numbness. It can develop in only a few hours in skin exposed to cold. The first aid treatment of chilblains is to stop exposure to cold, remove any wet or constrictive clothing, gently wash and dry the injured area, elevate it, cover it with layers of loose warm clothes and allow to rewarm. Like other kinds of cold injury such as trench foot and frostbite, chilblains may occur with and without freezing of body tissues. The young and the elderly are especially prone to cold injury. Alcohol increases the risk of cold injury which can lead to loss of body parts and even to death. "Chilblain" is an old English term compounded from chill + blain, an archaic word for a inflamed swelling or sore on the body.
Childbed fever (childbirth fever):  Fever due to an infection usually of the placental site within the uterus. The fever is also called childbirth fever or puerperal fever. If the infection involves the bloodstream, it constitutes puerperal sepsis. In Latin a puerpera is a woman in childbirth since puer means child and parere means to give birth. The puerperium is the time immediately after the delivery of a baby.
Childhood ataxia with central nervous system hypomyelinization:  An inherited brain disease that occurs mainly in children and follows a chronic progressive course with additional episodes of rapid deterioration following stress from febrile infection or minor head trauma.
Childhood liver cancer:  Primary cancer of the liver (cancer that starts in the liver) in children, a relatively rare malignancy in children. There are 2 main types of primary liver cancer in children - hepatoblastoma and hepatocellular carcinoma. Hepatoblastomas usually occur before 3 years of age, whereas the incidence of hepatocellular carcinoma varies little with age between 0 and 19 years. The overall survival rate for children with hepatoblastoma is 70% but is only 25% for hepatocellular carcinoma.
Children of the dark (Children of the night):  Term applied sometimes to children with xeroderma pigmentosum, a genetic disease with such extraordinary sensitivity to sunlight that ordinary sun exposure results in the development of skin cancer at a very early age. Children with xeroderma pigmentosum (XP) can only play outdoors safely after nightfall.
Chimera:  In medicine, a person composed of two genetically distinct types of cells. Human chimeras were first discovered with the advent of blood typing when it was found that some people had more than one blood type. Most of them proved to be "blood chimeras" - non-identical twins who shared a blood supply in the uterus. Those who were not twins are thought to have blood cells from a twin that died early in gestation. Twin embryos often share a blood supply in the placenta, allowing blood stem cells to pass from one and settle in the bone marrow of the other. About 8% of non-identical twin pairs are chimeras. Many more people are microchimeras and carry smaller numbers of foreign blood cells that may have passed from mother across the placenta, or persist from a blood transfusion. In vitro fertilization (IVF) is also contributing to the number of human chimeras. To improve success rates, two or more embryos are placed in the uterus so women who have IVF have more twin pregnancies than usual. More twins mean more chimeras. In Greek mythology, the Chimera was an awesome fire-breathing monster with the head of a lion, the body of a goat, and the tail of a serpent. The Chimera was killed by the hero Bellerophon mounted, in most versions of the tale, on Pegasus, the winged horse.
Chimeraplasty:  A method of gene therapy based upon the use of a molecule called a chimeraplast, a synthetic blend of DNA and the related molecule RNA, to trick the patient's own cells to remedy a gene defect. Chimeraplasts are made to match the patient's sequence of base pairs (the molecular building blocks of DNA), except in one area, the area of the mutation (the change) that is responsible for the gene defect. There, the chimeraplasts have the correct sequence of base pairs in the DNA. The chimeraplasts are designed to attach to the patient's DNA and activate the DNA repair system, a system that cells normally use to correct mistakes they make in replicating their DNA. The patient's DNA repair system is tricked into treating the chimeraplast as the correct version of the DNA and changing the patient's gene to match the chimeraplast, thus correcting the mutation.
Chinese restaurant syndrome:  A syndrome first described in 1968 in people who had eaten Chinese food on which MSG (monosodium glutamate) had been lavished. The syndrome only seems to occur in some people. Their symptoms may include headache, throbbing of the head, dizziness, lightheadedness, a feeling of facial pressure, tightness of the jaw, burning or tingling sensations over parts of the body, chest pain, and back pain. However, insomnia may be the only effect. Large amounts of MSG may cause arterial dilatation (widening of arteries). Many Chinese do not believe in the existence of the Chinese restaurant syndrome. It may be a hypersensitive (allergic) reaction. MSG is a sodium salt of the amino acid glutamic acid that enhances the flavor of certain foods. Originally isolated from seaweed, MSG is now made by fermenting corn, potatoes and rice. It does not enhance the four basic tastes (bitter, salty, sour, sweet) but it does enhance the complex flavors of meat, poultry, seafood, and vegetables. MSG is an important ingredient in the cuisines of China and Japan and is used commercially worldwide in many types of foods. It is naturally present at high levels in tomatoes and Parmesan cheese. In China, MSG is known as wei jing, which means flavor essence.
Chiron:  In Greek mythology, the centaur who, wounded by Hercules, invented medicine in order to heal himself. Chiron taught Asclepius the art of healing, which became the source of all divine medical knowledge among the Greeks. In astronomy the twin planet of Pluto.
Chiropractic:  A system of diagnosis and treatment based on the concept that the nervous system coordinates all of the body's functions, and that disease results from a lack of normal nerve function. Chiropractic employs manipulation and adjustment of body structures, such as the spinal column, so that pressure on nerves coming from the spinal cord due to displacement (subluxation) of a vertebral body may be relieved. Practitioners believe that misalignment and nerve pressure can cause problems not only in the local area, but also at some distance from it. Chiropractic treatment appears to be effective for muscle spasms of the back and neck, tension headaches, and some sorts of leg pain. It may or may not be useful for other ailments. Modern chiropractic was founded by Daniel David Palmer, a grocer, who performed his first chiropractic adjustment in 1895. The term "chiropractic" derived from the Greek "chir-" referring to the hand + "prassein", to do = to do with the hands (to manipulate) dates to 1898, the year Palmer founded the Palmer College of Chiropractic in Davenport, Iowa.
Chiropractor:  Someone who practices chiropractic.
Chloride:  The major anion (negatively charged substance) in the blood and extracellular fluid (the body fluid that lies outside cells). Blood and other body fluids have almost the same concentration of chloride ion as sea water. The balance of chloride ion (Cl-) is closely regulated by the body. Significant increases or decreases in chloride can have deleterious and even fatal consequences. Hyperchloremia: Abnormally high blood chloride. Elevations in chloride may be seen in diarrhea, certain kidney diseases, and sometimes in overactivity of the parathyroid glands. Hypochloremia: Abnormally low blood chloride. Chloride is normally lost in the urine, sweat, and stomach secretions. Excessive loss can occur from heavy sweating, vomiting, and adrenal gland and kidney disease.
Chloroacetophenone (tear gas):  A riot control agent which belongs to a class of agents collectively known as control agents or "tear gas." Chloroacetophenone (CN), chlorobenzylidenemalononitrile (CS), chloropicrin (PS), bromobenzylcyanide (CA), dibenzoxazepine (CR), and combinations of these chemicals are employed as tear gas agents. Although CN and CS are the most commonly used agents, many other tear gas agents have been used worldwide. Most exposures are inhalational, ocular, or dermal and typically lead to complaints of eye, nose, and throat irritation; hacking cough; suffocation or choking sensation; and dyspnea. Although unlikely, high-dose exposures in an enclosed space may lead to the development of airway edema, noncardiogenic pulmonary edema, and possibly respiratory arrest and death.
Chloroform:  A clear volatile liquid with a strong smell like ether, chloroform was once administered by inhalation to produce anesthesia and given as an analgesic (to relieve pain) and a remedy for cough. It is quite toxic to the kidney and the liver. Sir James Young Simpson, a prominent obstetrician and a professor of medicine and midwifery in Edinburgh (Scotland), introduced chloroform as an anesthetic agent for childbirth in 1847. Chloroform came to be widely used for other procedures but its dangerous side effects have relegated it to the annals of medical history.
Chloroprene:  A possible carcinogen (cancer-causing agent) primarily used in the production of the elastomer polychloroprene (neoprene). The US government in 2000 classified chloroprene as "reasonably anticipated to be a human carcinogen." In laboratory animal studies of chloroprene, cancer was observed in multiple organs of multiple species following long-term inhalation exposures.
Chlorpyrifos:  An insecticide that has adverse neurological effects. Also known as Dursban. Chlorpyrifos causes weakness, vomiting, diarrhea and other ill effects in children. It can also cause blurred vision and memory loss. Anyone can be exposed when the chemical is applied in a backyard or a building and through residue on fruits or other foods. Dursban was in hundreds of products including some of Raid sprays, Hartz yard and kennel flea spray, and Black Flag liquid roach and ant killer. The US Environmental Protection Agency (EPA) banned chlorpyrifos from domestic use. The manufacture of chlorpyrifos for most residential uses and all uses where children could be exposed was to halt by December 2000 and its use for termite control was to be phased out by December 2001 in all buildings used by children.
Chlortetracycline:  The first drug of the tetracycline family, to be introduced (in 1948).
Choana: (Plural: choanae):  The passageway from the back of one side of the nose to the throat. There are two choanae, one on either side of the nose. The choanae must be open to permit breathing through the nose. The noun choana is less used than the adjective choanal, as in choanal atresia (blockage of the choanal passage) and choanal stenosis (narrowing of the choanal passage).
Chocolate:  A food or flavoring made from the seeds of the cacao or chocolate tree. Chocolate is rich in flavinoids, compounds that act as antioxidants. Flavinoids may also lower blood pressure and improve blood flow, by regulating the synthesis of nitric oxide, which dilates blood vessels. Flavinoids, like aspirin, help keep platelets from aggregating on vessel walls. Thus, chocolate may have health benefits, provided it is consumed in moderation.
Choking (object in airway):  Partial or complete obstruction of the airway can be due to a foreign body (e.g., food, a bead, toy, etc.) The onset of respiratory distress may be sudden with cough. There is often agitation in the early stage of airway obstruction. The signs of respiratory distress include labored, ineffective breathing until the person is not longer breathing (apneic). Loss of consciousness occurs if the obstruction is not relieved. Treatment of airway obstruction due to a foreign body includes: Adults: The Heimlich maneuver. Children over 1 year of age: A series of 5 abdominal thrusts (a children's version of the Heimlich maneuver. Infants under 1 year of age: A combination of 5 back blows (with the flat of the hand) and 5 abdominal thrusts (with 2 fingers on the upper abdomen).
Choking in children:  The compromise of a child's normal breathing by obstructing or compressing the trachea, a major health hazard for children. Putting things in their mouths is one of the ways that babies and small children explore the world. Anything that fits in their mouths can be a danger. Choking is usually caused by food, toys, and other small objects that can easily lodge in a child's small airway.
Cholangi-:  Relating to a bile duct. From the Greek chole meaning bile + a(n)geion meaning a vessel = a bile vessel.
Cholangiogram:  A radiologic procedure used to look at the gallbladder and bile ducts.
Cholangiography:  Radiographic examination of the bile ducts with contrast medium. The contrast medium may be administered orally or injected intravenously or percutaneously (through the skin).
Cholangiography, percutaneous transhepatic:  Radiographic examination of the liver and bile ducts done by inserting a thin needle through the skin into the liver and injecting contrast medium in order to visualize blockage of the liver and bile ducts.
Cholangitis:  Inflammation of the bile duct.
Cholecalciferol:  Vitamin D3.
Cholecyst:  The gallbladder. The word cholecyst is not much used today but it figures into a number of other terms to do with the gallbladder Cholecystectomy is removal of the gallbladder. Cholecystitis is inflammation of the gallbladder. Cholecystogram is an x-ray of the gallbladder.
Cholecystectomy:  Surgical removal of the gallbladder. This procedure may be done by laparoscopy or by open surgery.
Cholecystitis:  Inflammation of the gallbladder, a complication of gallstones which are formed by cholesterol and pigment (bilirubin) in bile. (Bile is produced in the liver and stored in the gallbladder). Cholecystitis is frequently associated with infection in the gallbladder. Risk factors for cholesterol gallstones include age, obesity, female gender, multiple pregnancies, birth control pills, and heredity. The most common symptom is pain in the upper abdomen. Diagnosis is usually made with ultrasound of the abdomen. Some patients have no symptoms. Patients with mild and infrequent symptoms may consider oral medication to dissolve gallstones. Surgery (standard or laparoscopic) is considered for patients with severe symptoms and for patient with cholecystitis. In alternative medicine gall bladder flushes are done which often expell stones and avoids the need for surgery.
Cholecystokinin:  Abbreviated CCK. A polypeptide hormone that stimulates the contraction of the gallbladder with release of bile and the secretion of pancreatic enzymes into the small intestine. CCK is secreted by cells lining the upper intestine in response to the presence of food and by the hypothalamus. Hypothalamic cholecystokinin is a neurotransmitter. Called also pancreozymin.
Cholelithiasis:  1. The presence of stones in the gallbladder or common bile duct. 2. The process of formation of such stones. From the Greek roots chole, bile + lithos, stone.
Cholera:  A devastating and sometimes lethal disease with intense vomiting and profuse watery diarrhea leading to dehydration which, unless immediately treated, may be fatal. Cholera was discovered in 1883 to be due to infection with Vibrio cholerae, a comma-shaped bacteria. The discovery was made by the great German bacteriologist Robert Koch (1843-1910). As head of a commission investigating the disease, Koch went to Egypt where an epidemic was taking place and there he found some sort of bacterium in the intestines of those dead of cholera but could neither isolate the organism nor infect animals with it. Later in 1883 Koch went to India, where he wrote that he succeeded in isolating "a little bent [bacilli], like a comma." He discovered that the bacteria thrived in damp dirty linen and moist earth and in the stools of patients with the disease. The key to treating cholera is prompt and complete replacement of the fluid and salt lost through the profuse diarrhea. Patients are rehydrated with an oral solution which is a prepackaged mixture of sugar and salts that is then mixed with water and drunk in large amounts. With prompt and complete oral rehydration, fewer than 1% of cholera patients now die.
Cholesterol:  The most common type of steroid in the body, cholesterol has gotten something of a bad name. However, cholesterol is a critically important molecule. It is essential to the formation of:
Bile acids (which aid in the digestion of fats)
Vitamin D
Progesterone
Estrogens
(estradiol, estrone, estriol)
Androgens
(androsterone, testosterone)
Mineralocorticoid hormones
(aldosterone, corticosterone) and
Glucocorticoid hormones
(cortisol).
Cholesterol is also necessary to the normal permeability and function of cell membranes, the membranes that surround cells.
Cholesterol ester transfer protein:  A protein that helps regulate the size of cholesterol particles and influence the process of atherogenesis (the formation of plaques in arteries).
Cholestin:  One of the three major preparations of red yeast rice, a tradition Chinese medicine now used to lower cholesterol. Cholestin is also known as Hypocol.
Chondrocalcinosis:  Calcium in cartilage, usually in a joint, as in osteoarthritis.
Chondroitin sulfate:  A glycosaminoglycan (formerly called a mucopolysaccharide) found in cartilage, bone, blood vessels and connective tissues.
Chondromalacia:  Abnormal softening or degeneration of cartilage. Chondro- refers to cartilage while malacia (from the Greek malakia, softness) means softening.
Chondromalacia patellae:  The patellofemoral syndrome (PFS), the most common cause of chronic knee pain. PFS characteristically causes vague discomfort of the inner knee area, aggravated by activity (running, jumping, climbing or descending stairs) or by prolonged sitting with knees in a moderately bent position (the so-called "theater sign" of pain upon arising from a desk or theater seat). The knee may be mildly swollen. If chronic symptoms are ignored, the loss of quadriceps strength may cause the leg to "give out."
Chondroplasia:  The formation of cartilage by specialized cells called chondrocytes.
Chondrosarcoma:  A malignant tumor that forms in cartilage cells (chondroplasts) and that produces cartilage matrix. Chondrosarcoma can be primary or secondary. Primary chondrosarcoma forms in bone and is found in children. Secondary chondrosarcoma arises from pre-existing benign defects of cartilage (such as an osteochondroma or enchondroma), usually after age 40. Treatment is mainly by surgery.
Chorda tympani:  A branch of the facial nerve (the seventh cranial nerve) that serves the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain.
Chordae tendineae:  Thread-like bands of fibrous tissue which attach on one end to the edges of the tricuspid and mitral valves of the heart and on the other end to the papillary muscles, small muscles within the heart that serve to anchor the valves.
Chordoma:  A form of bone cancer that usually starts in the lower spinal column.
Chorea:  Ceaseless rapid complex body movements that look well coordinated and purposeful but are, in fact, involuntary. Chorea was thought suggestive of a grotesque dance. The term "chorea" is derived from the Greek word "choreia" for dancing (as is choreography).
Choriocarcinoma:  A highly malignant tumor that arises from trophoblastic cells within the uterus. Choriocarcinoma tends to be invasive and to metastasize early and widely through both the venous and lymphatic systems. Choriocarcinoma is one of the two types of gestational trophoblastic tumor, the other being hydatidiform mole. Choriocarcinoma may follow any type of pregnancy. It is especially likely to occur with a hydatidiform mole (molar pregnancy). About 2 to 3% of hydatidiform moles are complicated by the development of choriocarcinoma. The prognosis for women with metastatic choriocarcinoma was once grim. It has markedly improved with the advent of multidrug chemotherapy. Patients with high-risk metastatic disease usually need aggressive multidrug chemotherapy. Women with low-risk metastatic disease are sometimes treated with a single drug. Overall, the cure rate for high-risk patients is 60 to 80%.
Chorion:  The outermost of the two fetal membranes - the amnion is the innermost --. which together surround the embryo. The chorion develops villi (vascular fingers) and gives rise to the placenta. In Greek, the word "chorion" means "skin or leather."
Chorionic villus sampling:  A procedure for first-trimester prenatal diagnosis. Chorionic villus sampling may be done between the eighth and tenth weeks of pregnancy. The aim is to diagnose severe abnormalities afflicting the fetus. In the procedure, tissue is withdrawn from the villi (vascular fingers) of the chorion, a part of the placenta, and examined. Chorionic villus sampling is referred to commonly as CVS.
Choroid:  In the eye, a thin vascular layer between the sclera and the retina. The choroid supplies blood to the retina and conducts arteries and nerves to other structures in the eye.
Choroidal melanoma:  Malignant melanoma that arises in the eye.
Choroiditis:  An inflammation of the layer of the eye behind the retina, either in its entirely (multifocal choroiditis) or in patches (focal choroiditis). Usually the only symptom is blurred vision.
Chrematophobia or chromatophobia:  An abnormal and persistent fear of money. Sufferers experience undue anxiety even though they realize their fear is irrational. They worry that they might mis-manage money or that money might live up to its reputation as "the root of all evil." Perhaps they remember well the ill fortune that befell the mythical King Midas. His wish that everything he touched be turned to gold was fulfilled, and even his food was transformed into gold. From the Greek chrimata, money + phobia. The "chrome" in "chromatophobia" may also be related to the Greek word "chroma" (color) because of the brilliant colors of ancient coins--for example, gold, silver, bronze and copper.
Chromatin:  The nucleoprotein material of chromosomes. Chromatin is essentially the substance of chromosomes. It is made up of DNA attached to a protein structure.
Chromatography, gas:  A type of automated chromatography (a technique used to separate mixtures of substances) in which the mixture to be analyzed is vaporized and carried by an inert gas through a special column and thence to a detection device. The special column can contain an inert porous solid (in gas-solid chromatography) or a liquid coated on a solid support (in gas-liquid chromatography). The basic aim with GC is to separate each component that was in the mixture so that it produces a different peak in the detection device output which is graphed on a chart recorder. GC is a valuable tool in biochemistry (and other fields of chemistry, as in the analysis of perfumes).
Chromesthesia:  A type of synesthesia in which which a nonvisual stimulus causes the individual to perceive color. Color hearing is a form of chromesthesia. In color hearing a musical tone elicits a color. One well-studied case involved an art teacher who had a range of consistent linkages between tone and color. For her, high octaves tended to evoke a lighter color value, while lower octaves evoked a darker color value. And rapid major chord tone sequences elicited rapid flashes of colors, "somewhat like fireworks exploding."
Chromosome:  A visible carrier of the genetic information. The 3 billion bp (base pairs) in the human genome are organized into 24 distinct, physically separate microscopic units called chromosomes. All genes are arranged linearly along the chromosomes. The nucleus of most human cells contains two sets of chromosomes, one set given by each parent. Each set has 23 single chromosomes--22 autosomes and an X or Y sex chromosome. (A normal female will have a pair of X chromosomes; a male will have an X and Y pair.)
Chronic:  This important term in medicine comes from the Greek chronos, time and means lasting a long time. A chronic condition is one lasting 3 months or more, by the definition of the U.S. National Center for Health Statistics. In ancient Greece, the "father of medicine" Hippocrates distinguished diseases that were acute (abrupt, sharp and brief) from those that were chronic. This is still a very useful distinction. Subacute has been coined to designate the mid-ground between acute and chronic.
Chronic fatigue syndrome:  A debilitating and complex disorder characterized by profound fatigue of six months or longer duration that is not improved by bed rest and that may be worsened by physical or mental activity. Persons with chronic fatigue syndrome (CFS) most often function at a substantially lower level of activity than they were capable of before the onset of illness. In addition to these key defining characteristics, patients report various nonspecific symptoms, including weakness, muscle pain, impaired memory and/or mental concentration, insomnia and post-exertional fatigue lasting more than 24 hours. In some cases, CFS can persist for years. There is a lot of confusion about CFS in medicine due to the obsessive need of medicine to classify disease down to the Nth degree. True CSF, in this author's point of view, is always a result of malfunction of the immune syatem. The cause relates to some combination of toxicity ( usually heavy metal, but not always) and chronic infection (often hidden).
Chronic leukemia:  Cancer of the blood cells (leukemia) that progresses slowly. There are various varieties named according to the types of white cells involved and the clinical course, and sometime the age of onset: chronic lymphocytic leukemia, chronic myelocytic leukemia, chronic myelogenous leukemia, juvenile chronic myelogenous leukemia, and chronic myeloid leukemia.
Chronic obstructive lung disease (COLD):  Any disorder that persistently obstructs bronchial airflow. COLD mainly involves two related diseases -- chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time. In asthma there is also obstruction of airflow out of the lungs, but the obstruction is usually reversible and between attacks of asthma the flow of air through the airways is usually good. COLD is also called chronic obstructive pulmonary disease (COPD).
Chronic otitis externa:  Chronic inflammation of the skin lining the external ear canal leading to the ear drum. Can be caused by a number of problems including bacterial infection, a chronic skin disorder (eczema or seborrhea), fungus (Aspergillosis), chronic irritation (hearing aids, Q-tips), allergy, chronic drainage from middle ear disease, a tumor (rare), or it may simply be due to a nervous habit of frequently scratching the ear. In most patients, more than one factor may be involved.
Chronic pancreatitis:  A form of pancreatitis in which there is persistent inflammation of the pancreas. Chronic pancreatitis causes attacks of abdominal pain, nausea and vomiting that are worsened by eating or drinking, especially alcohol. The chronic inflammation can cause progressive fibrosis and destruction of the pancreas resulting in a lack of pancreatic enzymes and insulin. Deficiency of pancreatic enzymes can interfere with the ability to digest fat while the lack of insulin can lead to diabetes. Recurrent attacks of acute pancreatitis are often superimposed on the chronic process. Chronic pancreatitis is most commonly due to alcoholism and idiopathic (unknown) causes. Microlithiasis (tiny gallstones) causes some cases of chronic pancreatitis. Rare causes include hereditary pancreatitis, hyperparathyroidism, and obstruction of the main pancreatic duct caused by stenosis, stones, or cancer.
Chronic phase:  Refers to the early stages of chronic myelogenous leukemia. The number of immature, abnormal white blood cells in the bone marrow and blood is higher than normal, but lower than in the accelerated or blast phase.
Chronic progressive external ophthalmoplegia:  Slowly progressive paralysis of certain eye muscles. abbreviated CPEO.
Chronic renal failure:  Slow progressive loss of kidney function over the span of years, resulting in permanent kidney failure. Chronic kidney disease is common and may go undiagnosed until the process is far advanced and renal failure is on the horizon. People with permanent kidney failure need dialysis or a transplanted kidney to do the work of their failed kidneys.
Chronic tamponade:  A situation in which a chronic excess of fluid inside the pericardial sac and thickening of the pericardial sac progressively compress the heart and impair its performance. The excess fluid in the pericardial sac acts to constrict the heart. The word "tamponade" comes directly from the French. The French verb "tamponner" means to plug up and, also, to smash into. Here the outpouring of fluid within the pericardial sac is slowly smashing into the heart.
Chronic wasting disease:  A transmissible spongiform encephalopathy (TSE) of North American deer and elk, a progressive neurodegenerative disorder that produces spongiform changes in the brain and chronic weight loss leading to the death of these animals. There is no known relationship between chronic wasting disease (CWD) and any other TSE of animals or people.
Chronicity:  Characterized by long duration. The state of being chronic.
Churg-Strauss syndrome:  A disease characterized by inflammation of small ateries and veins in persons with a history of asthma or allergy. Aside from the inflammation of blood vessels (angiitis or vasculitis), there are abnormally large number of certain white blood cells (eosinophils) and inflammatory nodular lesions (granulomatosis). Onset is generally between 15 to 70 years of age. Symptoms include fatigue, weight loss, inflammation of the nasal passages, numbness, and weakness. The diagnosis is confirmed by a biopsy of involved tissue. The disease can be severely debilitating and, if untreated, even fatal.
Chyle:  A fluid consisting of a mixture of lymphatic fluid (lymph) and chylomicrons that has a milky appearance. Chylomicrons are small fat globules composed of protein and lipid (fat) which are combined in the lining of the intestine. They may be referred to as food particles. Chylomicrons are found in the blood and in lymphatic fluid where they serve to transport fat from its port of entry in the intestine to the liver and to adipose tissue (fat).
Chylomicron:  A small fat globule composed of protein and lipid (fat). Chylomicrons are found in the blood and lymphatic fluid where they serve to transport fat from its port of entry in the intestine to the liver and to adipose (fat) tissue. After a fatty meal, the blood is so full of chylomicrons that it looks milky. The word "chylomicron" is made up of "chylo-", milky + "micron", small. = small milky (globules). The chylomicrons are synthesized (made) in the mucosa (the lining) of the intestine.
Chyme:  A pre-digested, acidified mass of food that passes from the stomach into the small intestine.
Ci (Curie):  Ci is the abbreviation for a Curie, a unit of radioactivity. (Specifically, the quantity of any radioactive nuclide in which the number of disintegrations per second is 3.7 X 10 to the 10th). Named for Marie and Pierre Curie who did pioneering research in radioactivity, distinguished alpha, beta, and gamma radiation, discovered polonium and radium, and isolated pure radium. They shared the Nobel Prizes in Physics (with A.H. Becquerel) in 1903 and, after Pierre's death, Marie received the Nobel Prize in Chemistry in 1911.
Cigar:  A small roll of tobacco leaf for smoking. The word "cigar," from the Spanish "cigarro," first appeared in English in 1730. In 1998, a National Cancer Institute report outlined cause-and-effect connections between cigar smoking and disease, including cancer of the mouth and lungs, heart disease and emphysema, and stressed the danger of secondhand cigar smoke. In 2000, cigars sold in the US were required to carry a label warning of health risks associated with cigars. The labels (rotated at 3-month intervals) read:

1. Cigar Smoking Can Cause Cancers Of The Mouth And Throat, Even If You Do Not inhale
2. Cigar Smoking Can Cause Lung Cancer And Heart Disease
3. Tobacco Use Increases The Risk Of Infertility, Stillbirth And Low Birth Weight
4. Cigars Are Not A Safe Alternative To Cigarettes
5. Tobacco Smoke Increases The Risk Of Lung Cancer And Heart Disease, Even In Nonsmokers

Cigarette:  A small roll of finely cut tobacco enclosed in a wrapper of thin paper designed for smoking. "Cigarettes are the only product sold on the free market that, when used as directed, can kill people." (L Chasan-Taber & M Stampfer, New Engl J Med 2001;345:1841-2) The word "cigarette" is the French diminutive of "cigare" (cigar), from the Spanish "cigarro."
Ciguatera:  Seafood poisoning due to ciguatoxin, a toxin acquired by eating fish that have consumed toxic single-celled marine organisms called dinoflagellates or fish that have consumed other fish that have become toxic. When someone eats these fish, they suffer seafood poisoning. Ciguatera can cause gastrointestinal, neuromuscular symptoms and respiratory problems. The gastrointestinal problems include abdominal pain, diarrhea, nausea and vomiting. The neuromuscular problems may include tingling around the lips, abnormal or impaired skin sensations, hot-to-cold reversal, vertigo, lack of muscle coordination, weakness and numbness, muscle pain, and itching. There may be respiratory paralysis. Ciguatera symptom strike shortly after eating tainted fish. Symptoms may recur up to 6 months. Death is uncommon, but is known. Fish with ciguatoxin come from the southeastern United States, Bahamian, and Caribbean regions, Hawaii, and subtropical and tropical areas worldwide including the central Pacific and northern Australia. Barracuda, amberjack, horse-eye jack, black jack, other large species of jack, king mackerel, large groupers, and snappers are particularly likely to contain ciguatoxin. Many other species of large fish-eating fish may also contain ciguatoxin.
Cilia (singlare cilium):  The fine hairlike projections from certain cells such as those in the respiratory tract that sweep in unison and help to sweep away fluids and particles. Some single-celled organisms use the rhythmical motion of cilia for locomotion. Cilia is the plural of cilium, a Latin word referring to the edge of the eyelid and, much later, to the eyelashes. In the same sense, cilia came to refer to the fine hairlike projections from cells.
Ciliary body:  Part of the eye, the ciliary body is a thin vascular (blood vessel-filled) middle layer of the eye shapped like a donut from which the lens of the eye is suspended by fine filaments called zonules.
Ciliary body melanoma (Intraocular melanoma):  An eye cancer in which the malignant cells arise in the part of the eye called the uvea. The uvea includes the iris (the colored part of the eye), the ciliary body (a muscle in the eye), and the choroid (a layer of tissue in the back of the eye). The uvea contains pigment-producing cells called melanocytes. When these cells become cancerous, the cancer is called a melanoma. Intraocular melanoma occurs most often in people who are middle aged.
Ciliary muscle:  One of the muscles that relax the zonules to enable the lens to change shape for focusing. The zonules are fibers that hold the lens suspended in position and enable it to change shape during accommodation.
Ciliary neuralgia:  A distinctive syndrome of headaches, better known today as cluster headache. There are two main clinical patterns of cluster headache -- the episodic and the chronic. Episodic: This is the most common pattern of cluster headache. It is characterized by 1-3 short attacks of pain around the eyes per day, with these attacks clustered over a stretch of 1-2 months followed by a pain-free remission, a breathing spell. The average length of remission is a year. Chronic: Characterized by the absence of sustained periods of remission, chronic cluster headache may start with no past history of cluster headaches, or it may emerge several years after the patient has experienced an episodic pattern of cluster headaches. The episodic and chronic forms of cluster headache may transform into one another, so it seems most likely that they are merely different-appearing clinical patterns of one and the same disease. Although the mechanisms underlying cluster headache and migraine may have a degree of commonality, cluster headache looks to be different and distinct as a disease from migraine. For example, propranolol is effective for migraine but not cluster headache while lithium benefits cluster headache syndrome but not migraine.
Circadian:  Refers to events occurring within a 24-hour period, in the span of a full (24-hour) day, as in a circadian rhythm. Circadian rhythmicity is a fundamental property possessed by all organisms. These rhythms are driven by an internal time-keeping system: a clock. Changes in the external environment, particularly in the light-dark cycle, entrain this biologic clock. Under constant environmental conditions devoid of time cues, rhythms driven by the clock show a period near, but usually not exactly equal to, 24 hours. Humans have an internal 24-hour clock which regulates our daily activities such as sleep and waking. Difficulties in readjusting our clock causes jet lag, work shift problems and some types of sleep disorders. Circadian clocks affect almost every level of our bodily functions. A gene for the biological clock in a mouse was identified and cloned in 1997, the first such gene to be identified at the molecular level in a mammal. The identification of the "Clock" gene was proved by restoring a functioning biological clock to a line of mutant mice which had lost normal circadian rhythms. This was done by inserting DNA for the "Clock" gene into developing embryos that lacked it. They were born with a normal biological clock and passed the gene for it on to their descendants. The discovery of this gene regulating behavior was thus accompanied by simultaneous proof that the gene has been located by 'rescuing' the lost function of the gene. The word "circadian" is a 20th-century invention. It was coined in 1959 from the Latin "circa" (around) + "diem" (a day).
Circle of Willis:  An arterial circle at the base of the brain that is of critical importance. The circle of Willis receives all the blood that is pumped up the two internal carotid arteries that come up the front of the neck and that is pumped from the basilar artery formed by the union of the two vertebral arteries that come up the back of the neck. All the principal arteries that supply cerebral hemispheres of the brain branch off from the circle of Willis. The circle of Willis is often not complete. Maximally, only a third of people enjoy a complete circle of Willis. This is of importance in the event that one of the major arteries (an internal carotid or vertebral artery) supplying the circle of Willis is occluded. The presence of a complete circle of Willis permits a continuing supply of blood to the entire brain and helps avert a stroke.
Circular breathing:  Inhaling through the nose and inflating the cheeks and neck with air at the same time. Some saxophone players do circular breathing; this may not be a safe practice since it may reduce blood flow to the brain. Perhaps this accounts for the eccentricities of Bill Clinton.
Circulation:  The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
Circulation, fetal:  The blood circulation in the fetus (the unborn baby). Before birth, the blood from the heart that is destined (in the pulmonary artery) for the lungs is shunted away from the lungs and returned to the greatest of arteries (the aorta). The shunt is through a short vessel called the ductus arteriosus. When this shunt is open, it is said to be a patent ductus arteriosus (PDA). The PDA usually closes at or shortly after birth and blood is permitted to course freely to the lungs. If it does not close properly the result is poorly oxygenated blood finding its way to the body without having passed through the lungs.
Circulatory system:  The system that moves blood throughout the body. The circulatory system is composed of the heart, arteries, capillaries, and veins. This remarkable system transports oxygenated blood from the lungs and heart throughout the body via the arteries. The blood goes through the capillaries which are situated between the arteries and veins. And the blood that has been depleted of oxygen by the body is then returned to the lungs and heart via the veins.
Circumcision:  Surgery that removes the foreskin (the loose tissue) covering the glans of the penis. Circumcision may be performed for religious or cultural reasons, or health reasons. Newborn circumcision diminishes the risk for cancer of the penis and lowers the risk for cancer of the cervix in sexual partners. It also decreases the risk of urinary tract infections and lowers the risk of sexually transmitted diseases, including especially HIV. The Latin circum- means around (or about). Circumcision is, literally, a cutting around. Circumcision dates back to prehistoric times. It is one of the oldest surgical operations known to have been performed by people.
Circumflex:  Curved like a bow. In anatomy, circumflex describes a structure that bends around like a bow. For example, the circumflex branch of the left coronary artery.
Cirrhosis:  An abnormal liver condition characterized by irreversible scarring of the liver. Alcohol and viral hepatitis B and C are among the many causes of cirrhosis. Cirrhosis can cause yellowing of the skin (jaundice), itching, and fatigue. Diagnosis of cirrhosis can be suggested by physical examination and blood tests, and can be confirmed by liver biopsy in some patients. Complications of cirrhosis include mental confusion, coma, fluid accumulation in the abdomen (ascites), internal bleeding, and kidney failure. Treatment of cirrhosis is designed to limit any further damage to the liver as well as complications. Liver transplantation is becoming an important option for patients with advanced cirrhosis.
Cirrhosis with diffuse degeneration of cerebral gray matter, Alpers disease: A progressive disease of the nervous system characterized by spas:  Cirrhosis with diffuse degeneration of cerebral gray matter or Alpers disease is a progressive disease of the nervous system characterized by spasticity, myoclonus and dementia and by liver problems with jaundice and cirrhosis. This disorder was first described by Alpers in 1931 as "Diffuse progressive degeneration of gray matter of cerebrum," usually begins early in life with convulsions. A continuous seizure (status epilepticus) is often the final event. Alper's has more than one cause. Some cases are inherited as autosomal recessive traits with both parents appearing normal. Other cases of Alpers disease are disorders of oxidative phosphorylation, including mitochondrial DNA depletion syndromes. (Phosphorylation is the addition of phosphate to an organic compound, such as the addition of phosphate to ADP [adenosine diphosphate] to form ATP [adenosine triphosphate] or the addition of phosphate to glucose to produce glucose monophosphate, through the action of enzymes known as phosphotransferases or kinases.) Alpers disease is also called progressive infantile poliodystrophy, and Alpers progressive infantile poliodystrophy.
Cisplatin:  An anticancer drug that belongs to the family of drugs called platinum compounds. Cisplatin is used in the treatment of a wide range of malignancies, including advanced cancer of the ovary, testis, and bladder. Cisplatin is given intravenously. Its full chemical name is cis-dichlorodiammineplatinum. An important cause of hyperplatinumemia is chemotherapy with such drugs.
Citrulline:  A non-standard amino acid that is not normally present in protein. Citrulline is created in the body as an intermediate in the conversion of the amino acid ornithine to arginine in a metabolic pathway called the urea cycle. Citrulline was first isolated from watermelon. The term citrulline was coined in 1930 from citrullus, the Latin name of the watermelon.
Citrulline antibody:  An antibody (an immune protein) directed against a circular peptide (a ring of amino acids) containing an unusual ("non-standard") amino acid called citrulline that is not normally present in peptides or proteins. (Citrulline is formed by the body as an intermediary in the conversion of the amino acid orthithine to arginine). The citrulline antibody provides the basis for a test of importance in rheumatoid arthritis. The citrulline antibody appears early in the course of rheumatoid arthritis and is present in the blood of most patients with the disease. When the citrulline antibody is detected in a patient's blood, there is a 90-95% likelihood that the patient has rheumatoid arthritis.
Clade:  Related organisms descended from a common ancestor. For example, isolate M of HIV-1 (the human immunodeficiency virus) consists of at least ten clades. Imported from the Greek, klados, branch.
Clap:  Gonorrhea, a bacterial infection transmitted by sexual contact. Gonorrhea is one of the oldest known sexually transmitted diseases (STDs). In women infected with this bacteria (Neisseria gonorrhoeae), 25-40% will also be infected with another bacteria that can cause another STD called chlamydia. Gonorrhea is NOT transmitted from toilet seats as is commonly thought. More than half of women infected with gonorrhea do not have any symptoms. If symptoms occur, they may include burning or frequent urination, yellowish vaginal discharge, redness and swelling of the genitals, and a burning or itching of the vaginal area. Untreated, gonorrhea can lead to severe pelvic infections and blindness in the newborn. Silver nitrate eyedrops are commonly given to newborns to provent this problem.
Clark level of invasion:  A method for determining the prognosis (outlook) with melanoma. The method was devised by the pathologist Wallace Clark and measures the depth of penetration of a melanoma into the skin according to anatomic layer. There are five Clark levels of invasion.
Claudication:  Limping. The word "claudication" comes from the Latin claudicare meaning to limp. The Roman emperor Claudius (who ruled from A.D. 41-54) was so named because he limped, probably because of a birth defect. Intermittent claudication is an aching, crampy, tired, and sometimes burning pain in the legs that comes and goes - it typically occurs with walking and goes away with rest - due to poor circulation of blood in the arteries of the legs.
Claudication, intermittent:  An aching, crampy, tired, and sometimes burning pain in the legs that comes and goes. It typically occurs with walking and goes away with rest and is due to poor circulation of blood in the arteries of the legs. In very severe claudication the pain is also felt ar rest. Intermittent claudication may occur in one or both legs and often continues to worsen over time. However, some people complain only of weakness in the legs when walking or a feeling of "tiredness" in the buttocks. Impotence is an occasional related complaint in men. The usually intermittent nature of the pain is due to narrowing of the arteries that supply the leg with blood, limiting the supply of oxygen to the leg muscles, a limitation that is felt especially when the oxygen requirement of these muscles rises with exercise. Intermittent claudication can be due to temporary artery narrowing due to vasospasm (spasm of the artery), permanent artery narrowing due to atherosclerosis, or complete occlusion (closure) of an artery to the leg. Another unrelated cause of intermittent claudication is what has been come to be called a "procoagulant" condition of the blood. This results from severe stress or infection and may not disappear after the stress or infection is gone. The blood tends to "sludge" and not flow through the capillary system freely. The condition is quite common, more so in men than women. It affects 1-2% of the population under 60 years of age, 3-4% of persons age 60 to 70 and over 5% of people over 70. The pulses in the legs and feet are evaluated on the clinical exam. Diagnostic tests include blood pressure measurements to compare the arms and legs, Doppler ultrasonography on the legs, duplex Doppler/ultrasound exam of the extremities to visualize arterial blood flow, an ECG, and arteriography (injecting dye that can be visualized in the arteries). By far the best treatment of intermittent claudication is intravenous chelation therapy with EDTA as this addresses both the condition of the blood and the condition of the arterial system. Enzymes and occasionally herparin are used to treat hypercoagulability.
Claudication, venous:  Limping and/or pain due to inadequate venous drainage, poor return of blood by the veins of the legs. This is usually due to varicose veins and can be successfully treated by sclerotherapy.
Claustrophobia:  An abnormal and persistent fear of closed spaces, of being closed in or being shut in, as in elevators, tunnels, or any other confined space. The fear is excessive (and quite common).
Clavicle:  The bone extending from the breastbone (sternum) at the base of the front of the neck to the shoulder.
Clavus:  Synonymous with corns. The word "clavus" is the Latin word for nail.
Clay-shoveler's fracture:  An uncommon breakage of the spine of the vertebrae from the lower neck or upper back as a result of stress. Clay-shoveler's fracture usually occurs in laborers who perform activities involving lifting weights rapidly with the arms extended. Examples of these activities include shoveling soil, rubble or snow up and over the head backwards, using a pickax or scythe, and pulling out roots.
Cleft lip:  The presence of one or two vertical fissures (clefts) in the upper lip - cleft lip can be on one side only (unilateral) or on both sides (bilateral) - resulting from failure of the normal process of fusion of the lip to come to completion during embryonic life. Cleft lip is one of the most common physical birth defects. On the average, one baby per 1,000 is born with a cleft lip.
Cleft palate:  An opening in the roof of the mouth (the palate) due to a failure of the palatal shelves to come fully together from either side of the mouth and fuse, as they normally should, during embryonic development. The opening in the palate permits communication between the nasal passages and the mouth. Surgery is needed to close the palate. Cleft palate is a common physical birth defects, although not as common as cleft lip. About 1 baby in 2,000 is born with cleft palate versus 1 baby in 1,000 with cleft lip.
Cleft palate prosthesis:  A prosthetic device designed to close the opening left by a cleft in the palate and thereby to improve feeding and speech.
Cleft uvula:  The uvula, the little V-shaped fleshy mass hanging from the back of the soft palate, is cleft. . Cleft uvula is a common minor anomaly occurring in about 1% of whites and 10% of Native Americans. Persons with a cleft uvula should not have their adenoids removed because, without the adenoids, they cannot achieve proper closure between the soft palate and pharynx while speaking and develop hypernasal speech. Also called bifid uvula.
Cleidocranial dysostosis:  A genetic (inherited) disorder of bone development characterized by: Absent or incompletely formed collar bones (the "cleido-" part refers to the clavicles, the collar bones) The child with this disorder can bring its shoulders together or nearly so; and typical cranial and facial abnormalities with square skull, late closure of the sutures of the skull, late closure of the fontanels (the soft spots), low nasal bridge, delayed eruption of the teeth, abnormal permanent teeth, etc. Also called cleidocranial dysplasia.
Click-murmur syndrome:  Mitral valve prolapse (also known as Barlow's syndrome), the most common heart valve abnormality, affecting 5-10% of the world population. Most patients have no symptoms and require no treatment, but some have fatigue and/or palpitations. The mitral valve prolapse can often be detected by a doctor during examination of the heart and confirmed with an echocardiogram. (Mitral valve prolapse: Drooping down or abnormal bulging of the mitral valve's cusps backward into the atrium during the contraction of the heart. Mitral valve prolapse is often an asymptomatic condition but it may be marked by mitral regurgitation with symptoms (as chest pain, fatigue, dizziness, dyspnea, or palpitations) with a tendency in some cases to endocarditis or ventricular tachycardia.)
Climacteric:  1. The menopause in women. 2. The corresponding time in the life of men.
Clinical:  1. Having to do with the examination and treatment of patients. 2. Applicable to patients. A laboratory test may be of clinical value (of use to patients).
Clinical aspirin resistance:  The inability of aspirin to protect a person from cardiovascular events such as heart attacks and strokes.
Clinical cytogenetics:  The application of chromosome studies to clinical medicine. For example, clinical cytogenetic testing is done to see if a child with possible Down syndrome has an extra chromosome #21, as is most often the case.
Clinical depression:  Depression that meets the DSM-IV criteria for a depressive disorder. The term is usually used to denote depression that is not a normal, temporary mood caused by life events or grieving.
Clinical disease:  A disease with clinical signs and symptoms that are recognizable. As distinct from a subclinical illness without clinical manifestations. Diabetes, for example, can be subclinical in someone before emerging as a clinical disease.
Clinical investigator:  A medical researcher who carries out a clinical trial or another type of clinical research.
Clinical psychology:  A professional specialty concerned with diagnosing and treating diseases of the brain, emotional disturbance, and behavior problems. Psychologists can only use talk therapy as treatment; you must see a psychiatrist or other medical doctor to be treated with medication. Psychologists may have a master's degree (MA) or doctorate (PhD) in psychology. They may also have other qualifications, including Board certification and additional training in a type of therapy.
Clinical trials:  Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.
Clinodactyly:  Curving of the fifth finger (the little finger) toward the fourth finger (the ring finger). Sometimes called "fifth finger clinodactyly" to distinguish it from similar curving of other finger or toes. Clinodactyly is a minor congenital malformation (birth defect). The basis for the clinodactyly is that the middle bone in the fifth finger is underdeveloped and, instead of being rectangular, is wedge- shaped. No treatment is required.
Clinophobia:  An abnormal and persistent fear of going to bed. Sufferers from clinophobia experience anxiety even though they realize that going to bed normally should not threaten their well-being. However, because they worry about having nightmares or wetting the bed, they often remain awake and develop insomnia. Insomnia then can become a real threat to their well-being.
Clitoral:  Pertaining to the clitoris, the small elongated erectile body in the female homologous with the penis in the male.
Clitoral amputation (Clitorectomy):  A surgical procedure in which all or part of the clitoris and sometimes also the labia are removed. Clitoral amputation is a form of female circumcision (female genital mutilation). Also called clitorectomy or clitoridectomy, it is practiced by some primitive cultures, Muslim and otherwise. It would appear to be a form of gynephobia and/or misogyny and designed to subjugate women.
Clitoris:  A small mass of erectile tissue situated at the anterior apex of the vestibule.
CLL:  Chronic lymphocytic leukemia.
Cloaca:  A common passageway for feces, urine and reproduction. At one point in the development of the human embryo, there is a cloaca. It is the far end of a structure called the hindgut. This structure then divides to form a rectum, a bladder, and genitalia. The presence of a cloaca is normal in many adult animals (birds, reptiles, amphibians, some fish, and even a few mammals). However, the persistence of a persistent cloaca in a person is a birth defect (a congenital malformation). Cloaca is the Latin word for drain or sewer.
Cloacal exstrophy:  A birth defect involving the pelvic area that is termed a malformation sequence and involves the cloaca.
Clone:  Literally a fragment, the word in modern medical science has come to mean a replica, for example, of a group of bacteria or a macromolecule such as DNA. Clone also refers to an individual developed from a single somatic (non-germ) cell from a parent, representing an exact replica of that parent. A clone is a group of cells derived from a single ancestral cell.
Clonic seizure:  A seizure in which there are generalized clonic (back and forth) contractions with the entire body jerking, but without a preceding tonic (stiffened) phase.
Cloning:  The process of making a clone, a genetically identical copy. Cloning can refer to the technique of producing a genetically identical copy of an organism by replacing the nucleus of an unfertilized ovum with the nucleus of a body cell from the organism. The first adult mammal cloned was Dolly the Sheep in 1997.
Cloning vector:  A DNA molecule originating from a virus, a plasmid (see below) or the cell of a higher organism into which another DNA fragment can be integrated without loss of the vector's (carrier's) capacity for self-replication. Cloning vectors are used to introduce foreign DNA into host cells, where that DNA can be reproduced (cloned) in large quantities.
Clonote:  The first cell produced by the combination of a nucleus and an enucleated ovum that launches the process of somatic-cell nuclear transfer (SCNT). As opposed to the zygote, the first cell resulting from fertilization. The term "clonote" was coined to connote the fundamental difference between in vitro fertilization (IVF) and SCNT. IVF (and the natural reproductive process) can lead to the production of a zygote and, in time, a human being whereas SCNT cannot. The term was created by merging clon(e) and (zyg)ote.
Clostridium:  A group of anaerobic bacteria (bacteria that thrive in the absence of oxygen). There are 100+ species of Clostridium.
Clotbuster:  An informal term for a drug that can dissolve a clot. Also called a thrombolytic agent.
Club drug:  A drug such as MDMA (Ecstasy), GHB, Rohypnol, ketamine, methamphetamine, and LSD that is used by young adults at all-night dance parties such as "raves" or "trances," dance clubs, and bars. Use of club drugs can cause serious health problems and, in some cases, death. No club drug is benign. Chronic abuse of MDMA, for example, appears to produce long-term damage to serotonin-containing neurons in the brain. Because some club drugs are colorless, tasteless, and odorless, they can be added unobtrusively to beverages by individuals who want to intoxicate or sedate others. In recent years, there has been an increase in reports of club drugs used to commit sexual assaults.
Clubfoot:  A common malformation of the foot that is evident at birth. The foot is turned in sharply so that the person seems to be walking on their ankle. The medical term for the common ("classic") type of clubfoot is talipes equinovarus. Clubfoot can sometimes, but not always, be corrected with a combination of surgery, bracing, and physical therapy. When it cannot be fully corrected, special shoes and braces are available to help the person achieve a more comfortable gait and avoid stressing and deforming other muscles and bones.
Cluster:  In epidemiology, an aggregation of cases of a disease or another health-related condition, such as a cancer or birth defect, closely grouped in time and place. The number of cases in the cluster may or may not exceed the expected number. This is determined by cluster analysis, a set of statistical methods used to analyze clusters.
Cluster headache:  A distinctive syndrome of headaches, also known as migrainous neuralgia. There are two main clinical patterns of cluster headache - the episodic and the chronic. The Episodic: This is the most common pattern of cluster headache. It is characterized by 1-3 short attacks of pain around the eyes per day, with these attacks clustered over a stretch of 1-2 months followed by a pain-free remission, a breathing spell. The average length of remission is a year. The Chronic: Characterized by the absence of sustained periods of remission, chronic cluster headache may start with no past history of cluster headaches, or it may emerge several years after the patient has experienced an episodic pattern of cluster headaches. The episodic and acute forms of cluster headache may transform into one another, so it seems most likely that they are merely different-appearing clinical patterns of one and the same disease. Although the mechanisms underlying cluster headache and migraine may have a degree of commonality, cluster headache looks to be different and distinct as a disease from migraine. For example, propranolol is effective for migraine but not cluster headache while lithium benefits cluster headache syndrome but not migraine.
CMV (cytomegalovirus):  A virus that infects 50-85% of adults in the US by age 40 and is also the virus most frequently transmitted to a child before birth. Persons with symptoms have a mononucleosis-like syndrome with prolonged fever and mild hepatitis. Once a person becomes infected, the virus remains alive and usually dormant within that person's body for life. Recurrent disease rarely occurs unless the person's immune system is suppressed due to therapeutic drugs or disease. CMV infection is therefore a concern because of the risk of infection to the unborn baby, people who work with children, and immunodeficient people such as transplant recipients and those with HIV.
CNS (central nervous system):  That part of the nervous system that consists of the brain and spinal cord. The central nervous system (CNS) is one of the two major divisions of the nervous system. The other is the peripheral nervous system (PNS), that part of the nervous system that lies outside the brain and spinal cord.
CNS prophylaxis:  Chemotherapy or radiation therapy to the central nervous system (CNS). This is preventative treatment. It is given to kill cancer cells that may be in the brain and spinal cord, even though no cancer has been detected there.
Co-morbid:  Pertaining to two or more disorders simultaneously.
Coagulation:  In medicine, the clotting of blood. The process by which the blood clots to form solid masses, or clots. More than 30 types of cells and substances in blood affect clotting. The process is initiated by blood platelets. Platelets produce a substance that combines with calcium ions in the blood to form thromboplastin, which in turn converts the protein prothrombin into thrombin in a complex series of reactions. Thrombin, a proteolytic enzyme, converts fibrinogen, a protein substance, into fibrin, an insoluble protein that forms an intricate network of minute threadlike structures called fibrils and causes the blood plasma to gel. The blood cells and plasma are enmeshed in the network of fibrils to form the clot.
Coagulation, laser:  The coagulation (clotting) of tissue using a laser. A coagulation laser produces light in the visible green wavelength that is selectively absorbed by hemoglobin, the pigment in red blood cells, in order to seal off bleeding blood vessels. There is also, for example, electrocoagulation and photocoagulation.
Coal miner's lung (black lung disease):  A chronic occupational lung disease contracted by the prolonged breathing of coal mine dust. The silica and carbon in the coal dust cause black lung disease. About one of every 20 miners studied in the US has X-ray evidence of black lung disease, a form of pneumoconiosis. In its early stages, called simple pneumoconiosis, the disease does not prevent the miner from working or carrying on most normal activities. In some miners, the disease never becomes more severe. In other miners, the disease progresses from simple to complicated pneumoconiosis, a condition also called progressive massive fibrosis. Pneumoconiosis is not reversible. There is no specific treatment.
Coarctation:  A narrowing, a stricture, a constriction. Although the best known coarctation is of the aorta, any artery can have a coarctation. The word "coarctation" comes from the Latin "coartare" meaning :to press together." The sides of the vessel at the point of a coarctation appear pressed together.
Coarctation of the aorta:  A congenital constriction of the aorta, impeding the flow of blood below the level of the constriction and increasing blood pressure above the constriction. Symptoms may not be evident at birth but may develop as soon as the first week after birth with congestive heart failure or high blood pressure that call for early surgery. The surgery otherwise can be delayed. The outlook after surgery is favorable. Some cases have been treated by balloon angioplasty. The word "coarctation" comes from the Latin "coartare" meaning :to press together." The sides of the aorta at the point of a coarctation appear pressed together.
Coated stent:  Also known as a medicated stent. A tiny cage coated with a drug to prop open an artery and prevent it from closing again. The stent is a minute metal mesh tube. It is inserted into a coronary artery usually just after an angioplasty has been done to open the vessel. The stent slowly releases the drug with which it is coated. The drug may, for example, be sirolimus. Coated stents reduce the risk of artery re-narrowing, or restenosis, after angioplasty which occurs about a third of the time when bare metal stents are used. However, a coated stent is appreciably more costly than an uncoated one ($3,200 versus $1,000, in 2003). A little known and little communicated fact is that stints have never been approved by the FDA and are considered experimental.
Cobalamin:  Vitamin B12. A vitamin important for the normal formation of red blood cells and for the health of the nerve tissues. Undetected and untreated vitamin B12 deficiency can lead to anemia and permanent nerve and brain damage. Forms of cobalamin include methyl-lcobalamine and hydroxy-cobalamine.
Cocaine:  The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America. From the name of the plant came the name cocaine and its street name coke (and Coke as in Coca Cola, which once contained it). Once the American surgeon William S. Halstead (1852-1922) had injected cocaine into nerve trunks and showed it numbed feeling, cocaine came into use as an anesthetic agent. It was first employed as a spinal anesthetic in 1898 by the German surgeon August Bier. Soon thereafter the addictiveness of cocaine was discovered. Safer anesthetics were developed in the 20th century and cocaine fell into disuse in medicine as a pain blocker. Tragically, cocaine continues in use as a highly addictive and destructive street drug, an inadvertent contribution by medicine to the contemporary drug culture.
Cocci:  pleural of coccus. Bacteria which are spherically shaped.
Coccidioidomycosis:  A disease due to a fungus called Coccidioides immitis. About 40% of people infected with this fungus develop symptoms. Most often they have an influenza-like illness with fever, cough, headaches, rash, and myalgias (muscle pains). Of those people with symptoms, 8% have severe lung disease requiring hospitalization and 7% develop disseminated infection (throughout the body). Groups at high risk from the fungus include African-Americans and Asians, pregnant women in the third trimester, smokers, the elderly, diabetics and people with an impaired immune system. The fungus can infect the retina and cause blindness. The disease is also known by a number of other names including desert fever, Posadas disease, San Joaquin fever, San Joaquin Valley disease, San Joaquin Valley fever, and valley fever. (Oh, and by the way, it is endemic in the San Joaquin Valley of California.) The fungus is in the soil in semiarid areas (primarily in the "lower Sonoran life zone"). The disease is endemic (constantly present) in the southwestern US and parts of Mexico and South America. Inhalation of airborne spores after disturbance of soil by people or natural disasters (such as wind storms and earthquakes) exposes people (as for example, construction or agricultural workers and archeologists) to the dust containing the spores. A mask helps but does not provide complete protection against the fungus.
Coccus:  A bacterial cell which has the shape of a sphere. Coccus enters into the name of a number of bacteria. For example, enterococcus, meningococcus, pneumococcus, staphylococcus, and streptococcus.
Coccydynia:  Pain in the coccyx (the tailbone). The coccyx is the small bone at the bottom of the spine very near the anus. The coccyx is made up of 3-5 rudimentary vertebrae and is the lowest part of the spinal column.
Coccygeal:  Referring to the coccyx, the small tail-like bone at the bottom of the spine, that is made up of 3-5 (average of 4) rudimentary vertebrae. There is a coccygeal nerve that originates in the spinal cord and emerges at the level of the coccyx.
Coccygeal vertebrae:  The coccyx, the small tail-like bone at the bottom of the spine near the anus, is made up of 3-5 (average of 4) rudimentary vertebrae.
Coccyx:  The small tail-like bone at the bottom of the spine very near to the anus. The coccyx is made up of 3-5 rudimentary vertebrae. It is the lowest part of the spinal column. The word "coccyx" comes from the Greek "kokkyx" meaning "cuckoo bird." It got this name because it was thought to look like the bill of the cuckoo.
Cochlea:  The part of the inner ear that converts mechanical energy (vibrations) into nerve impulses sent to the brain. It is also known as the organ of hearing. The cochlea is a small conical structure resembling a snail shell. The word "cochlea" is a Latin word derived from the Greek "kokhlos" designating the land snail. A coiled tube, the cochlea winds two and three quarters turns about a central bony axis, forming the front (the anterior) part of the labyrinth (a maze within the inner ear). The cochlea contains the spiral organ (called the organ of Corti) which is the receptor for hearing.
Cochlear implant:  A small complex electronic device that is surgically placed (implanted) within the inner ear to help persons with certain types of deafness to hear. Cochlear implants rarely cure severe or profound deafness but they can help some hearing-impaired people to distinguish the sounds of language clearly enough to participate in a verbal environment. For children who are congenitally deaf (born deaf), a cochlear implant can markedly increase the child's chance of being able to function effectively in mainstream school classes. A cochlear implant has four basic parts: a microphone, which picks up sound from the environment; a speech processor, which selects and arranges sounds picked up by the microphone;a transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses; and electrodes, which collect the impulses from the stimulator and send them to the brain. Whereas hearing aids amplify sound, cochlear implants compensate for damaged or non-working parts of the inner ear. A cochlear implant electronically finds useful sounds and then sends them to the brain. Deaf children who receive cochlear implants in infancy tend to have neurological development closest to that of hearing children. Adults who have lost all or most of their hearing later in life may also benefit from cochlear implants. These older candidates can often associate the sounds made through an implant with sounds they remember. This may help them to understand speech without visual cues or systems such as lipreading or sign language.
Cockayne syndrome:  A genetic disorder that involves progressive multisystem degeneration and is classified as a segmental premature-aging syndrome. Cockayne syndrome is characterized by dwarfism, prematurely aging, visual problems and deafness, sensitivity to sunlight, and mental retardation.
Cockle:  The ventricle of the heart.
Cockroach allergy:  A condition that manifests as an allergic reaction when one is exposed to tiny particles from cockroaches. Asthma can be due to exposure to cockroach allergens (allergy-provoking substances). These substances are the proteins shed or excreted by the cockroaches.
Cod liver oil:  An oil extracted from the liver of the cod fish. Cod liver oil was once given religiously to children every day as a rich source of vitamins A and D. It was also used to treat children with rickets, a bone disease due to vitamin D deficiency. Cod liver oil is now known to be rich in omega-3 fatty acids. Perhaps because of this, cod liver oil helps slow the destruction of joint cartilage in osteoarthritis. Anyone who was ever given cod liver oil, even years ago, can still remember its distasteful odor and foul taste. It reportedly comes in more palatable forms today.
Codon:  A set of any three adjacent bases in the DNA or RNA. There are 64 different codons.
Coefficient of inbreeding:  A measure of how close two people are genetically to each another. The coefficient of inbreeding, symbolized by the letter F, is the probability that a person with two identical genes received both genes from one ancestor. Take a first-cousin mating. First cousins share a set of grandparents. For any particular gene in the male, the chance that his female first cousin inherited the same gene from the same source is 1/8. Further, for any gene the man passes to his child, the chance is 1/8 that the woman has the same gene and ½ that she transmits that gene to the child so 1/8 X ½ = 1/16. Thus, a first-cousin marriage has a coefficient of inbreeding F =1/16. The added risks for the offspring of first cousins depend not only upon the coefficient of inbreeding but also upon the genetic family history and test results. For example, first cousins of Italian descent are at increased risk of carrying a gene for beta thalassemia and genetic laboratory tests may confirm that they are both beta-thalassemia gene carriers. There are always added risks in the mating of closely related persons and those risks are not entirely negligible.
Coenzyme:  A substance that enhances the action of an enzyme. (An enzyme is a protein that functions as a catalyst to mediate and speed a chemical reaction). Coenzymes are small molecules. They cannot by themselves catalyze a reaction but they can help enzymes to do so. In technical terms, coenzymes are organic nonprotein molecules that bind with the protein molecule (apoenzyme) to form the active enzyme (holoenzyme). A number of the water-soluble vitamins such as vitamins B1, B2 and B6 serve as coenzymes.
Coenzyme Q10:  A compound needed for the proper functioning of an enzyme, a protein that speeds up the rate at which chemical reactions take place in the body. Coenzyme Q10 is used to produce energy to fuel cell growth and maintenance. Coenzyme Q10 is thought to improve the function of mitochondria, the "powerhouses" that produce energy in cells. Coenzyme Q10 is also an antioxidant, a substance that protects cells from highly reactive chemicals called free radicals that can damage cells and their DNA. The highest amounts of coenzyme Q10 are in the heart, liver, kidneys, and pancreas and the lowest amounts are in the lungs. The levels of coenzyme Q10 normally decline with age.
Coffin-Lowry syndrome:  An X-linked form of mental retardation in which the affected males have short stature and characteristic face, finger and skeletal abnormalities. Facial features include prominent forehead, widespread eyes, downslanting eyeslits, prominent ears, thick lips and irregular/missing teeth. The hands are large and soft with lax skin and tapering fingers. Skeletal changes include kyphosis/scoliosis and pectus carinatum (pigeon breast) or pectus excavatum (caved-in chest). The syndrome is due to mutation of the gene on the X chromosome that encodes RSK2, a growth-factor regulated protein kinase.
Cogan corneal dystrophy:  A disorder in which the cornea (the normally clear front window of the eye) shows grayish fingerprint lines, geographic map-like lines, and dots (or microcysts) on examination with a slit-lamp that focuses a high intensity light beam as a slit while the examiner looks at the front of the eye through a magnifying scope. The disorder is usually silent and without symptoms. However, about one patient in ten has recurrent erosion of the cornea that usually begins after the age 30. Conversely, half of patients with recurrent corneal erosions of idiopathic (unknown) origin have this disorder. Under the microscope, a structure called the epithelial basement membrane is abnormal so the disorder is sometimes called epithelial basement corneal dystrophy. The disorder was first described by Cogan and colleagues in 1964.
Cogan syndrome:  Arteritis (inflammation of the arteries, also referred to as vasculitis) that involves the ear. This condition is called Cogan syndrome after the American ophthalmologist David Glendenning Cogan (1908-1993) who first described it. Cogan syndrome features not only problems of the hearing and balance portions of the ear, but also inflammation of the front of the eye (the cornea) and often fever, fatigue, and weight loss. Joint and muscle pains can also be present. Less frequently, the arteritis can involve blood vessels elsewhere in the body as in the skin, kidneys, nerves, and other tissues and organs. Cogan syndrome can lead to deafness or blindness. The treatment of Cogan syndrome is directed toward stopping the inflammation of the blood vessels. Cortisone-related medications, such as prednisone, are often used. Some patients with severe disease can require immune suppression medications.
Cognition:  The process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging.
Cognitive:  Pertaining to cognition.
Cognitive science:  is the study of the mind. It is an interdisciplinary science that draws upon many fields including neuroscience, psychology, philosophy, computer science, artificial intelligence, and linguistics. The purpose of cognitive science is to develop models that help explain human cognition -- perception, thinking, and learning. The central tenet of cognitive science is that the mind is an information processor. This processor receives, stores, retrieves, transforms, and transmits information. The information and the corresponding information processes can be studied as patterns.
Cognitive therapy:  A relatively short-term form of psychotherapy based on the concept that the way we think about things affects how we feel emotionally. Cognitive therapy focuses on present thinking, behavior, and communication rather than on past experiences and is oriented toward problem solving. Cognitive therapy has been applied to a broad range of problems including depression, anxiety, panic, fears, eating disorders, substance abuse, and personality problems. Cognitive therapy is sometimes called cognitive behavior therapy because it aims to help people in the ways they think (the cognitive) and in the ways they act (the behavior).
Cohort:  In a clinical study, a well-defined group of subjects or patients who have had a common experience or exposure and are then followed up for the incidence of new diseases or events, as in a cohort study.
Cohort study:  A study in which a particular outcome, such as death from a heart attack, is compared in groups of people who are alike in most ways but differ by a certain characteristic, such as smoking.
Coitophobia:  An abnormal and persistent fear of male-female sexual intercourse. Sufferers from coitophobia experience undue anxiety because they are preoccupied with failing in some way while having heterosexual intercourse. Among the symptoms of coitophobia are failure to achieve an erection (erectile dysfunction) and failure to achieve orgasm (anorgasmy).
Coitus:  Sexual union of a male and a female; also called sexual intercourse.
Coitus interruptus:  A method of contraception, also called withdrawal, in which the man withdraws his penis from the vagina before ejaculation. Fertilization is prevented because the sperm do not enter the vagina. The effectiveness of this maneuver depends on the man's ability to withdraw before the ejaculation of any sperm. Withdrawal does not provide protection from sexually transmitted diseases (STDs) such as HIV. Infectious diseases can be transmitted by direct contact with surface lesions and by pre-ejaculatory fluid.
Coke:  Street name for cocaine, the most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America. From the name of the plant came the name cocaine and its street name coke (and Coke as in Coca Cola, which once contained it).
Colchicine:  A substance found in a plant that is used in clinical medicine for the treatment of gouty arthritis and in the laboratory to arrest cells during cell division (by disrupting the spindle) so their chromosomes can be visualized. The name colchicine is from the Greek kolchikon meaning autumn crocus or meadow saffron, the plant from which colchicine was originally isolated.
COLD (chronic obstructive lung disease):  Any disorder that persistently obstructs bronchial airflow. COLD mainly involves two related diseases - chronic bronchitis and emphysema. Both bronchitis and emphysema cause chronic obstruction of air flowing through the airways of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time. By contrast, in asthma there is also obstruction of airflow out of the lungs, but the obstruction is usually reversible and between attacks of asthma the flow of air through the airways is usually good. COLD is also called chronic obstructive pulmonary disease (COPD).
Cold injury:  Cold injuries include chilblains, "trench foot," and frostbite. Cold injuries occur with and without freezing of body tissues. The young and the elderly are especially prone to cold injury. Alcohol increases the risk of cold injury which can lead to loss of body parts and even to death. It is important not to thaw an extremity if there is a risk of it re-freezing.
Cold sore:  A small sore situated on the face or in the mouth that causes pain, burning, or itching before bursting and crusting over. The favorite locations are on the lips, chin or cheeks and in the nostrils. Less frequented sites are the gums or roof of the mouth (the palate).
Cold, common:  A viral upper respiratory tract infection. This contagious illness can be caused by many different types of viruses, and the body can never build up resistance to all of them. For this reason, colds are a frequent and recurring problem. In fact kindergarten children average 12 colds per year, while adolescents and adults have around seven colds per year. Going out into the cold weather is not how one contracts a cold nor does it have an effect on the spread of a cold. Antibiotics do not cure or shorten the common cold. Prevention of colds with nutritional medicine is a reasonable goal. This author has not had a cold in the last eight years.
Colectomy:  Surgery during which all or part of the colon (also called the large intestine) is removed. There are a number of different types of colectomies. They include: right hemicolectomy - in which the right part of the colon is removed, left hemicolectomy - where the left portion of the colon is removed, and other types of partial colectomies - where other segments are removed from the colon. In all colectomies, the bowel is either reconnected afterward (which is called an anastomosis) or the surgeon creates an ostomy, an opening of the bowel on the abdominal wall, to allow the contents of the bowel to exit from the body. Colectomy may be needed for treatment of different types of problems, including diverticulitis, benign polyps of the colon and cancer of the colon. A special variant of colectomy is total colectomy, which is also called proctocolectomy. This is most commonly a treatment considered for people with ulcerative colitis, either because of failure to respond to treatment or because of the cancer risk associated with the disease.
Colic:  An attack of crying and apparent abdominal pain in early infancy. This is a common condition, occurring in about 1 in every 10 babies. Colic is characterized by episodes of irritability, loud crying, and what appears to be abdominal pain with the legs drawn up and the abdomen feeling rigid. An attack of colic usually begins suddenly, often after a feeding. The cry is loud and continuous. The spells last from one to four hours and the baby's face often gets flushed or red. The belly is sometimes distended or prominent; the legs alternate between flexed and extended straight out; the feet are often cold and the hands clenched. The episodes, while they can occur at any time of the day or night, typically begin in the late afternoon or early evening. Overfeeding, undiluted juices, food allergies, and emotional stress can aggravate colic. Colic usually lasts from several weeks of age to 3 to 4 months of age. It is not harmful to the baby but is very consternating and wearing on parents. Parents should not assume new abdominal pain and loud crying in their baby is colic. It is important for the baby to be seen by a doctor to rule out other more serious conditions.
Colitis:  Inflammation of the large intestine (the colon). There are many forms of colitis, including ulcerative, Crohn's, infectious, pseudomembranous, and spastic. For example, intermittent rectal bleeding, crampy abdominal pain and diarrhea can be symptoms of ulcerative colitis. Diagnosis can be made by barium enema, but direct visualization (sigmoidoscopy or colonoscopy) is the most accurate test. Long-standing ulcerative colitis increases the risk for colon cancer. Ulcerative colitis can also be associated with inflammation in joints, spine, skin, eyes, the liver and its bile ducts.
Colitis, amebic:  Amebic dysentery (inflammation of the intestine) with ulcers in the colon due to infection with an ameba (Entamoeba histolytica), a single-celled parasite transmitted to humans via contaminated water and food. Ameba is from the Greek amoibe meaning "change" because amebae constantly change shape.
Colitis, Crohn's (Also know as granulomatous colitis): Crohn's disease affecting only the large intestine (colon). Crohn's di:  
Colitis, mucus:  A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although the disorder can cause chronic recurrent discomfort, it does not lead to any serious organ problems. Treatment is directed toward relief of symptoms and includes changes in diet (eating high fiber and avoiding caffeine, milk products and sweeteners), exercise, relaxation techniques, and medications.
Colitis, pseudomembranous:  Severe inflammation of the inner lining of the colon due usually to the Clostridium difficile (C.difficile) bacterium, one of the most common causes of infection of the large bowel (colon) in the United States, affecting millions of patients yearly. Patients taking antibiotics are at risk of becoming infected with C. difficile. Antibiotics disrupt the natural bacteria of the bowel, allowing C. difficile bacteria to become established in the colon. Many persons infected with C. difficile bacteria have no symptoms. These people become carriers of the bacteria and can infect others. In some people, a toxin produced by C. difficile causes diarrhea, abdominal pain, severe inflammation of the colon (colitis), fever, an elevated white blood count, vomiting and dehydration. Rarely, the walls of the colon wear away and holes develop (colon perforation), which can lead to a life-threatening infection of the abdomen.
Colitis, spastic:  A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although the disorder can cause chronic recurrent discomfort, it does not lead to any serious organ problems. Treatment is directed toward relief of symptoms and includes changes in diet (eating high fiber and avoiding caffeine, milk products and sweeteners), exercise, relaxation techniques, and medications.
Colitis, universal:  Ulcerative colitis that involves the entire colon (the large intestine).
Collagen:  Collagen is the principal protein of the skin, tendons, cartilage, bone and connective tissue.
Collagen disease:  A disease (autoimmune or otherwise) that attacks the collagen or other components of connective tissue, such as lupus.
Collagen injection:  The practice of injecting collagen into a part of the face or body to make it larger, most often performed on the lips. The effects are long lasting but not permanent. Collagen injections are normally done by a plastic surgeon.
Collagenopathy:  Any one of a group of disorders that affect connective tissue, the tissue that supports the body's joints and organs. The collagenopathies are caused by defects in type II or type XI collagen. Collagens are complex molecules that provide structure, strength, and elasticity (the ability to stretch) to connective tissue. The conditions are considered together because type II and type XI collagen are both components of a particular type of cartilage (hyaline cartilage) in joints and the spinal column, the inner ear, and the jelly-like substance that fills the eyeball (the vitreous), resulting in similar clinical features.
Collapsed lung:  Failure of full expansion of a once fully expanded lung. Medically called atelectasis.
Collapsing Pulse:  A jerky pulse that is full and then collapses because of aortic insufficiency (when blood ejected into the aorta regurgitates back through the aortic valve into the left ventricle). This type of pulse was likened to a water hammer, a Victorian toy consisting of a glass tube filled partly with water or mercury in a vacuum. The water or mercury produced a slapping impact when the glass tube was turned over. Also called a Corrigan pulse or a cannonball, water-hammer, pistol-shot, or trip-hammer pulse.
Collarbone:  A horizontal bone above the first rib that makes up the front part of the shoulder. The collarbone, also called the "clavicle," links the sternum, or breastbone, with the scapula, a triangular bone in the back of the shoulder. The collarbone ends at the sternum, forming one side of the sternoclavicular joint. It ends at the shoulder, there forming one side of the acromioclavicular joint.
Collateral:  In anatomy, a collateral is a subordinate or accessory part. A collateral is also a side branch, as of a blood vessel or nerve. After a coronary artery occlusion, collaterals (that is, collateral vessels) often develop to shunt blood around the blockage.
Collateral knee ligament, lateral:  The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide stability and strength to the knee joint. The lateral collateral ligament of the knee is on the outside of the joint (and the medial collateral ligament in on the inside.)
Coloboma:  A congenital malformation (birth defect) in which part of the eye does not form due to failure of fusion of an embryonic feature called the intraocular fissure. The resultant coloboma can be likened to a missing slice from a pie that may involve a number of different structures within the eye including the choroid, iris, lens, optic nerve, and retina. A coloboma can occur as an isolated defect in an otherwise normal baby, or it can be part of a multiple congenital malformation syndrome such as the cat-eye syndrome (named after the coloboma which gives the eye something of a feline look).
Colography:  a "virtual colonoscopy" using CAT scan technology.
Colon:  The part of the large intestine that runs from the cecum to the rectum as a long hollow tube that serves to remove water from digested food and let the remaining material, solid waste, move through it to the rectum and leave the body. The colon measures about 5 ft (1.5 m) in length. It goes up (the ascending colon) on the right side of the abdomen, across the abdomen (the transverse colon) beneath the stomach, and then down (the descending colon) on the left side of the abdomen and makes a sharp turn in the left lower portion (the sigmoid colon) to merge with the rectum. The colon is sometimes inaccurately called the large intestine or large bowel. It is only a part of the large intestine/bowel, the rectum comprising the rest of the large intestine.
Colon cancer:  A malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colonic polyps. Removal of these precancerous polyps can prevent colon cancer. Colon polyps and early colon cancers cause no signs or symptoms. Full-blown colon cancer can cause occult (a microscopic amount of) blood in the stool, overt rectal bleeding, bowel obstruction, and weight loss. Risk factors for colon cancer include a family history of it or of colonic polyps, and long standing ulcerative colitis. The overall risk can be reduced by following a diet low in fat and high in fiber. Colon cancer is preventable and curable. It is preventable by removing the precancerous colon polyps. It is curable if detected early when it can be surgically removed before it has spread to other parts of the body. If screening and surveillance programs were practiced universally, there would be a tremendous reduction in the incidence and mortality of colon cancer.
Colon cancer and polyps:  Benign tumors of the large intestine are called polyps. Malignant tumors of the large intestine are called cancers. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can be easily removed during colonoscopy, and are not life threatening. If benign polyps are not removed from the large intestine, they can become malignant (cancerous) over time. Most of the cancers of the large intestine are believed to have developed from polyps.
Colon cancer family history:  A family history of colorectal cancer (CRC). First-degree relatives of people with CRC are themselves at a 2 to 3-fold increased risk of colorectal cancer. (Parents, brothers and sisters, and children are first-degree relatives.) When the family history includes 2 or more relatives with CRC, the possibility of an inherited CRC syndrome is increased.
Colon polyp:  A fleshy growth on the inside (the lining) of the colon (the large intestine). Colon polyps are extremely common. Their incidence increases as individuals get older. Half of all people over the age of 60 harbor at least one polyp. Polyps give rise to colon cancer, the second leading cause of death from cancer in the US. Screening for colon polyps and removing them before they become cancerous markedly reduces the incidence of colon cancer. Colon polyps are more properly referred to as colorectal polyps since they occur in the rectum, too. Colorectal polyps are conventionally divided into two groups - non-neoplastic polyps and neoplastic polyps (also called adenomatous polyps or adenomas). The nonneoplastic polyps have not been considered precursors (forerunners) of cancer while the neoplastic polyps are precursors of colorectal cancer.
Colon syndrome, nervous:  A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although the disorder can cause chronic recurrent discomfort, it does not lead to any serious organ problems. Making the diagnosis usually involves excluding other illnesses. Treatment is directed toward relief of symptoms and includes changes in diet (eating high fiber and avoiding caffeine, milk products and sweeteners), exercise, relaxation techniques, and medications. Alternative names include irritable bowel syndrome (IBS), spastic colitis, and mucus colitis.
Colonic (colonic irrigation, colon therapy, colon cleansing):   the infusion of warm water into the colon through a tube in the rectum. Infusion and expulsion of water is repeated 10-15 times over one hour.
Colonoscope:  A flexible, lighted instrument used to view the inside of the colon.
Colonoscopy:  A procedure in which a long flexible viewing tube (a colonoscope) is threaded up through the rectum for the purpose of inspecting the entire colon and rectum and, if there is an abnormality, taking a biopsy of it or removing it. The colonoscopy procedure requires a thorough bowel cleansing to assure a clear view of the lining. Also called also coloscopy.
Colonoscopy, virtual:  A method for examining the colon by taking a series of x-rays and then using a computer to reconstruct three-dimensional pictures (a CT scan) of the interior surfaces of the colon from these x-rays. The pictures can be saved, manipulated to better viewing angles, and reviewed after the procedure. The procedure requires a 48-hour low-fiber diet and a complete bowel cleansing. If something suspicious is noted, a regular colonoscopy is needed to biopsy or remove it. Virtual colonoscopy results in about 15% false positives (misleading readings that unnecessarily require a regular colonoscopy). It is also not yet known whether virtual colonoscopy can reliably detect flat adenomas which, like polyps, can give rise to colon cancer. Also called computed tomography or CT colography.
Colony-stimulating factor:  A laboratory-made agent similar to a substance in the body that stimulates the production of blood cells. Treatment with colony-stimulating factors (CSFs) can help the blood- forming tissue recover from the effects of chemotherapy and radiation therapy. The CSFs include granulocyte colony-stimulating factors (G-CSF) and granulocyte-macrophage colony-stimulating factors (GM-CSF).
Colorblindness:  The inability to perceive colors in a normal fashion. The most common forms of colorblindness are inherited as sex-linked (X-linked) recessive traits. Females are carriers and males are affected. As a result, approximately 1 in 8 males is colorblind as compared to less than 1 in 100 females. The most common form of colorblindness is red-green. There is a wide range of variability within this group from very mild to extreme. The second most common form is blue-yellow. A red-green deficit is almost always associated with this form. The most severe form of colorblindness is achromatopsia, the inability to see any color. It is often associated with other eye problems such as amblyopia (lazy eye), nystagmus, photosensitivity, and extremely poor vision. The symptoms of red-green and blue-yellow colorblindness may be so mild that affected people are unaware they are colorblind unless specifically tested. Parents may notice colorblindness in a more severely affected child at the time the child would normally learn colors. Several color vision tests are available through a primary physician or an eye specialist (ophthalmologist). Testing for colorblindness is commonly performed along with other vision screenings. There is no known treatment. People with this condition need to learn to cope. Colorblindness is a life-long condition. Colorblindness may exclude people from some jobs, such as being a pilot, where color vision is essential. People with red-green colorblindness may also fail to notice the presence of blood in the urine and stool.
Colorblindness, red-green:  A form of colorblindness in which red and green are perceived as identical. This is the most common type of colorblindness. It is also known as deuteranomaly, deuteranopia, and Daltonism. The term "Daltonism" is derived from the name of the chemist and physicist, John Dalton (1766-1844) who had this disorder.
Colorectal:  Related to the colon and/or rectum.
Colorectal adenomatous polyposis, recessive:  Autosomal recessive form of colorectal adenomatous polyposis.
Colorectal cancer:  Cancer of the colon and rectum. A malignant tumor arising from the inner wall of the large intestine. Risk factors include heredity, colon polyps, and long standing ulcerative colitis. Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer. Since colon polyps and early cancer can have no symptoms, regular screening is important. Diagnosis can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue. Surgery is the most common treatment for colorectal cancer.
Colostomy:  An alternative exit from the colon created to divert waste through a hole in the colon and through the wall of the abdomen. A colostomy is commonly performed by severing the colon to attach the end leading to the stomach to the skin through the wall of the abdomen. The end of the colon that leads to the rectum is closed off and becomes dormant. This is known as a "Hartmann's Colostomy". There are other types of colostomy procedures, but this one is the most common. Usually a colostomy is performed for infection, blockage, or in rare instances, severe trauma of the colon. This is not an operation to be taken lightly. It demands the close attention of both patient and doctor. A colostomy is often performed so that an infection can be stopped and/or the affected colon tissues can heal.
Colostomy bag:  A removable, disposable bag that attaches to the exterior opening of a colostomy (stoma) to permit sanitary collection and disposal of bodily wastes.
Colostomy, iliac:  A colostomy in which the exterior opening (stoma) is located on the lower left side of the abdomen.
Colostomy, transverse:  A colostomy in which the exterior opening (stoma) is located on the upper abdomen.
Colostrum:  A sticky white or yellow fluid secreted by the breasts during the second half of pregnancy and for a few days after birth before the breast milk comes in.
Colpo-:   Combining form referring to the vagina, as in colposcopy (inspection of the vagina) and colpotomy (incision of the vagina). From the Greek kolpos meaning a fold, cleft, or hollow.
Colpocephaly:  A brain disorder in which there is an abnormal enlargement of the occipital horns of the brain --the posterior or rear portion of the lateral ventricles (cavities or chambers) of the brain. This enlargement occurs when there is an underdevelopment or lack of thickening of the white matter in the posterior cerebrum. Colpocephaly is characterized by microcephaly (abnormally small head) and mental retardation. Other features may include motor abnormalities, muscle spasms, and seizures. The cause of colpocephaly is unknown. A disturbance occurs between the second and sixth months of pregnancy. Colpocephaly may be diagnosed late in pregnancy, although it is often misdiagnosed as hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain). It may be more accurately diagnosed after birth when signs of mental retardation, microcephaly, and seizures are present. There is no definitive treatment for colpocephaly. Anticonvulsant medications can be given to prevent seizures, and doctors try to prevent contractures (shrinkage or shortening of muscles). The prognosis for individuals with colpocephaly depends on the severity of the associated conditions and the degree of abnormal brain development. Some children benefit from special education.
Colpopexy:  The use of surgical-quality stitches to bring a displaced vagina back into position against the abdominal wall.
Colpoptosis:  A condition in which the vagina has dropped from its normal position against the abdominal wall.
Colporrhaphy:  Surgical repair of the vagina. The -rrhaphy part of the word comes from the Greek raphe meaning suture.
Colposcope:  A lighted magnifying instrument used by a gynecologist to examine the tissues of the vagina and the cervix. The procedure is called colposcopy.
Colposcopy:  A procedure in which a gynecologist uses a lighted magnifying instrument which is called a colposcope to examine the tissues of the vagina and the cervix.
Colpotomy:  A surgical incision in the vagina. The -tomy part of the word comes from the Greek tome meaning cutting.
Coma:  A state of deep unarousable unconsciousness. A state in which many doctors exist.
Coma, diabetic:  Coma in a diabetic due to the buildup of ketones in the bloodstream. Ketones are a product of metabolizing (using) fats rather than the sugar glucose for energy. The best approach to diabetic coma is prevention. Careful diet, medication, and insulin dosing as needed should prevent ketone build-up. Patients with diabetes and their family members should be aware of the early signs of ketone build-up. These include weight loss, nausea, confusion, gasping for breath, and a characteristically sweet, chemical odor similar to that of acetone or alcohol ("acetone breath") to the patient's breath and sometimes sweat. Diabetic coma may be heralded by confusion and convulsions. Immediate emergency medical treatment is needed in a hospital setting for patients who show the early signs of diabetic coma.
Combined oral contraceptive:  Commonly called "the pill," combined oral contraceptives are the most commonly used form of reversible birth control in the United States. This form of birth control suppresses ovulation (the monthly release of an egg from the ovaries) by the combined actions of the hormones estrogen and progestin. If a woman remembers to take the pill every day as directed, she has an extremely low chance of becoming pregnant. But the pill's effectiveness may be reduced if the woman is taking some medications, such as certain antibiotics. Besides preventing pregnancy, the pill can make periods more regular. It also has a protective effect against pelvic inflammatory disease (PID), an infection of the fallopian tubes or uterus that is a major cause of infertility in women, and against ovarian and endometrial cancers. Current low-dose pills have fewer risks associated with them than earlier versions. But women who smoke, especially those over 35, and women with certain medical conditions such as a history of blood clots or breast or endometrial cancer, may be advised against taking the pill. The pill may also contribute to cardiovascular disease, including high blood pressure, blood clots, and blockage of the arteries. The side effects of the pill include nausea, headache, breast tenderness, weight gain, irregular bleeding, and depression. These side effects often subside after a few months' use of the pill. This author does not recommend the use of oral contraception due to the possible ill effects. There are other methods of birth control and they are effective and safe is performed correctly. Along with abortion on demand "the pill" sparked a sexual revolution in the 60s and 70s which was only reined in with the advent of AIDS in the 80s. The psychological and moral consequences of this revolution are still being observed and debated.
Comedo:  The primary sign of acne consisting of a dilated (widened) hair follicle filled with keratin squamae (skin debris), bacteria, and sebum (oil). A comedo may be closed or open. A closed comedo has an obstructed opening to the skin and may rupture to cause a low-grade skin inflammatory reaction in the area. The common name for a closed comedo is a whitehead. Plural is comedones.
Commensal:  1. Living in a relationship in which one organism derives food or other benefits from another organism without hurting or helping it. Commensal bacteria are part of the normal flora in the mouth. 2. An intimate relationship. The Norway rat, roof rat, and house mouse are considered commensal rodents because of their intimate relationships with humans.
Comminuted fracture:  A fracture in which bone is broken, splintered or crushed into a number of pieces.
Common acute lymphocytic leukemia antigen: (CALLA):  A cell surface enzyme with neutral metalloendopeptidase activity that serves as a marker for the common form of ALL (acute lymphocytic leukemia) as well as for Burkitt lymphoma and follicular germinal center lymphoma. CALLA is normally present on the surface of early lymphoid cells as well as on a number of other types of normal cells, such as especially cells in the kidney.
Common bile duct:  The duct that carries bile from the gallbladder and liver into the duodenum (the upper part of the small intestine). The common bile duct is formed by the junction of the cystic duct that comes from the gallbladder and the common hepatic duct that comes from the liver.
Common cold:  A viral upper respiratory tract infection. This contagious illness can be caused by many different types of viruses, and the body can never build up resistance to all of them. For this reason, colds are a frequent and recurring problem. In fact kindergarten children average 12 colds per year, while adolescents and adults have around seven colds per year. Going out into the cold weather is not how one contracts a cold nor does it have an effect on the spread of a cold. Antibiotics do not cure or shorten the common cold. While many doctors will tell you it is "normal" to have 8 or more colds per year, in fact it is surely a sign of an unbalanced immune system. This condition is so common that it is considered normal. This author has not had a cold for several years.
Common hepatic duct:  The duct formed by the junction of the right hepatic duct (which drains bile from the right half of the liver) and the left hepatic duct (which drains bile from the left half of the liver). The common hepatic duct then joins the cystic duct coming from the gallbladder to form the common bile duct.
Common migraine:  Migraine without aura. The most frequent type, accounting for about 80-85% of migraine.
Commotio cordis:  Sudden cardiac arrest from a blunt, nonpenetrating blow to the chest. The basis of the cardiac arrest is ventricular fibrillation (a chaotically abnormal heart rhythm) triggered by chest wall impact immediately over the anatomic position of the heart. This can happen, for example, in sports such with baseballs, softballs, lacrosse balls, hockey pucks and a blow in boxing. The only effective treatment is cardiopulmonary resuscitation with defibrillation to reverse ventricular fibrillation. Commotio cordis ia also known as a "concussion of the heart."
Community-acquired infection:  An infection acquired in the community. In contrast to a nosocomial infection (hospital-acquired).
Comorbidity:  The coexistence of two or more disease processes.
Compartment syndrome:  A condition in which there is swelling and an increase in pressure within a limited space (a compartment) that presses on and compromises blood vessels, nerves, and/or tendons that run through that compartment. Hence, the function of tissue within that compartment is compromised. Compartment syndromes usually involve the leg but can also occur in the forearm, arm, thigh, shoulder, and buttock. Some of the causes of increased pressure in compartment syndromes are trauma (for example, a fracture), too-tight wound dressings or casts, hemorrhage (bleeding) into the compartment, or inflammation (carpal tunnel syndrome, for example). Symptoms of a compartment syndrome include numbness, tingling, pain or loss of movement in an extremity. Sequelae (the lasting effects) can include nerve compression, paralysis, contracture or even death. Treatment is to relieve the pressure; if symptoms are severe or prolonged, surgery may be needed.
Compassionate use:  Term used in the US for a method of providing experimental therapeutics prior to final FDA approval for use in humans. This procedure is used with very sick individuals who have no other treatment options. Often, case-by-case approval must be obtained from the FDA for "compassionate use" of a drug or therapy.
Complement system:  A series of molecules that work together to perform many immune system functions. For example, the complement system helps to dissolve and remove immune complexes and to kill foreign cells.
Complementary DNA:  Single-stranded DNA made in the laboratory from a messenger RNA template under the aegis of the enzyme reverse transcriptase. This form of DNA is often used as a probe in the physical mapping of a chromosome.
Complementary medicine:  A group of diagnostic and therapeutic disciplines that are used together with conventional medicine. An example of a complementary therapy is using aromatherapy to help lessen a patient's discomfort following surgery. Complementary medicine is usually not taught or used in Western medical schools or hospitals. Complementary medicine includes a large number of practices and systems of health care that, for a variety of cultural, social, economic, or scientific reasons, have not been adopted by mainstream Western medicine. Complementary medicine is different from alternative medicine. Whereas complementary medicine is used together with conventional medicine, alternative medicine is used in place of conventional medicine.
Complete androgen insensitivity syndrome:  A genetic disorder that makes XY fetuses insensitive (unresponsive) to androgens (male hormones). Instead, they are born looking externally like normal girls. Internally, there is a short blind-pouch vagina and no uterus, fallopian tubes or ovaries. There are testes in the abdomen or the inguinal canal. The complete androgen insensitivity syndrome is usually detected at puberty when a girl should but does not begin to menstruate. Many of the girls with the syndrome have no pubic or axillary (armpit) hair. They have luxuriant scalp hair without temporal (male-pattern) balding. They are sterile and cannot bear children. They are at high risk for osteoporosis and so should take estrogen replacement therapy.
Complete blood count:  A set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute. The values generally included are the following:

White blood cell count (WBC). The number of white blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4,300 and 10,800 cells per cubic millimeter (cmm). This can also be referred to as the leukocyte count and can be expressed in international units as 4.3 - 10.8 x 109 cells per liter.

Automated white cell differential. A machine generated percentage of the different types of white blood cells, usually split into granulocytes, lymphocytes, monocytes, eosinophils, and basophils.

Red cell count (RBC). The number of red blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4.2 - 5.9 million cells/cmm. This can also be referred to as the erythrocyte count and can be expressed in international units as 4.2 - 5.9 x 1012 cells per liter.

Hemoglobin (Hb). The amount of hemoglobin in a volume of blood. Hemoglobin is the protein molecule within red blood cells that carries oxygen and gives blood its red color. Normal range for hemoglobin is different between the sexes and is approximately 13 - 18 grams per deciliter for men and 12 - 16 for women (international units 8.1 - 11.2 millimoles/liter for men, 7.4 - 9.9 for women).

Hematocrit (Hct). The ratio of the volume of red cells to the volume of whole blood. Normal range for hematocrit is different between the sexes and is approximately 45 - 52% for men and 37 - 48% for women.

Mean cell volume (MCV). The average volume of a red cell. This is a calculated value derived from the hematocrit and red cell count. Normal range is 86 - 98 femtoliters.

Mean cell hemoglobin (MCH). The average amount of hemoglobin in the average red cell. This is a calculated value derived from the measurement of hemoglobin and the red cell count. Normal range is 27 - 32 picograms.

Mean cell hemoglobin concentration (MCHC). The average concentration of hemoglobin in a given volume of red cells. This is a calculated volume derived from the hemoglobin measurement and the hematocrit. Normal range is 32 - 36%.

Red cell distribution width (RDW). A measurement of the variability of red cell size. Higher numbers indicate greater variation in size. Normal range is 11 - 15.

Platelet count. The number of platelets in a volume blood. Platelets are not complete cells, but actually fragments of cytoplasm from a cell found in the bone marrow called a megakaryocyte. Platelets play a vital role in blood clotting. Normal range varies slightly between laboratories but is in the range of 150,000 - 400,000/ cmm (150 - 400 x 109/liter).

Complete hysterectomy:  Complete surgical removal of the uterus and cervix. Also called a total hysterectomy.
Complete syndactyly:  A condition in which fingers or toes are completely joined together, with the connection extending from the base to the tip of the involved digits. Complete syndactyly is the opposite of partial syndactyly, in which the connection extends only part of the way up from the base of the involved digits. The word "syndactyly" is compounded from the Greek roots "syn-" (together) + "dactylos" (finger) = fingers together.
Completely-in-the-canal hearing aid:  The smallest and most discreet of the common styles of hearing instruments. Completely-in-the-canal (CIC) hearing aids are custom designed to fit entirely in the ear canal, improving sound quality and reducing feedback. CICs are appropriate for mild to moderate hearing losses and for sloping high-frequency hearing losses, but not for infants or young children.
Complex partial seizure:  A form of partial seizure during which the person loses awareness. The patient does not actually become unconscious, and he or she may carry out actions as complex as walking, talking, or driving. The patient may have physical, sensory, and thought disturbances. When the seizure ends, the patient has no memory of those actions.
Complicated grief:  Sadness over loss that is complicated by adjustment disorders (especially depressed and anxious mood or disturbed emotions and behavior), major depression, substance abuse, and post-traumatic stress disorder. It is defined by the extended length of time of the symptoms, the interference in normal function caused by the symptoms, or by the intensity of the symptoms (for example, intense suicidal thoughts or acts).
Complication:  In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication makes the situation more complex and more difficult to deal with.
Complications, postoperative:  Postoperative problems affecting patients after surgery. Postoperative complications may (or may not) be directly related to the disease for which the surgery was done or to the surgery itself.
Compound fracture:  A fracture in which the bone is protruding through the skin. Also called an open fracture.
Compound microscope:  A microscope which consists of two microscopes in series, the first serving as the ocular lens (close to the eye) and the second serving as the objective lens (close to the object to be viewed). Credit for creating the compound microscope goes usually to the Dutch spectacle makers Hans and Zacharias Janssen who in 1590 invented an instrument that could be used as either a microscope or telescope. The compound microscope has evolved into the dominant type of optical microscope today.
Compress:  1. As a noun, a cloth or another material applied under pressure to an area of the skin and held in place for a period of time. A compress can be any temperature (cold, luke warm, or hot) and it can be dry or wet. It may also be impregnated with medication or, in traditional medicine, an herbal remedy. Most compresses are used to relieve inflammation. 2. As a verb, to squeeze or press together. An injury can compress the spinal cord.
Compression:  1. The act of pressing together. As in a compression fracture, nerve compression, or spinal cord compression. 2. To shorten in time. In embryology, there may be compression of development with some stages even omitted.
Compression fracture:  A fracture caused by compression, the act of pressing together. Compression fractures of the vertebrae are especially common with osteoporosis.
Compulsive shopping:  An obsession with shopping that significantly interferes with the functioning of the individual. The signs are a preoccupation with shopping; anxiety when not shopping; a constant need for a shopping "fix"; shopping to excess that results in debt and family or marital discord; and the frequent purchase of items that go unused. Although there is debate as to whether compulsive shopping is a mental disorder, there is evidence that use of an antidepressant medication tends to lessen anxiety and decrease or stop compulsive shopping.
Computed tomography:   An x-ray procedure that uses the help of a computer to produce a detailed picture of a cross section of the body. Also called a CT scan or CAT scan.
Computer addiction:  A disorder in which the individual turns to the Internet or plays computer games in an attempt to change moods, overcome anxiety, deal with depression, reduce isolation or loneliness, or distract themselves from overwhelming problems. The elderly, as well as children and adolescents, are particularly vulnerable because they may not realize the extent of their dependency. In many instances, individuals with computer addiction may seek help for another condition, such as depression, phobias or other addictions.
Computerized axial tomography (CAT):  Cat scanning adds X-ray images with the aid of a computer to generate cross-sectional views anatomy. It can identify normal and abnormal structures and be used to guide procedures. CAT scanning is painless. Iodine-containing contrast material is sometimes used in CAT scanning. If you are having a CAT scan and are allergic to iodine or contrast materials, you should notify your physicians and radiology staff. CAT scanning was invented in 1972 by the British engineer Godfrey N. Hounsfield (later Sir Godfrey) and the South African (later American) physicist Alan Cormack. CAT scanning was already in general use by 1979, the year Hounsfield and Cormack were awarded the Nobel Prize in Medicine or Physiology for its development. The CAT scan is also known as the CT (computerized tomography) scan.
Computerized axial tomography scan:  Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures. The CAT (computerized axial tomography) scan can reveal some soft-tissue and other structures that cannot be seen in conventional X-rays. Using the same dosage of radiation as that of an ordinary X-ray machine, an entire slice of the body can be made visible with about 100 times more clarity with the CAT scan. The "cuts"(tomograms) for the CAT scan are usually made 5 or 10 mm apart. The CAT machine rotates 180 degrees around the patient's body; hence, the term "axial." The machine sends out a thin X-ray beam at 160 different points. Crystals positioned at the opposite points of the beam pick up and record the absorption rates of the varying thicknesses of tissue and bone. The data are then relayed to a computer that turns the information into a 2-dimensional cross-sectional image.
Concato's Disease (Polyserositis):  Chronic inflammation of several serous membranes with effusions in serous cavities resulting in fibrous thickening of the serosa and constrictive pericarditis.
Conception:  1. The union of the sperm and the ovum. Synonymous with fertilization. 2. The onset of pregnancy, marked by implantation of the blastocyst into the endometrium.
Concordance:  1. The presence of any given condition such as HIV in both members of a couple. 2. In genetics, the presence of a phenotype such as asthma in both members of a twin pair. 3. In clinical care, agreement between physician and patient. In every case, concordance is as opposed to discordance. From the Latin concordare, to agree.
Concussion:  A traumatic injury to tissues of the body such as the brain as a result of a violent blow, shaking, or spinning. A brain concussion can cause immediate and usually temporary impairment of brain function such as of thinking, vision, equilibrium and consciousness.
Condyloma:  A wartlike growth around the anus, vulva, or glans penis. There are three major types of condylomas, each of which is sexually transmitted. These include condyloma acuminatum or genital warts, condyloma latum (a form of secondary syphilis), and condyloma subcutaneum or molluscum contagiosum.
Condyloma acuminatum (Genital wart):  A wart in the moist skin of the genitals or around the anus. Genital warts are due to a human papillomavirus (HPV). The HPVs, including those that cause genital warts, are transmitted through sexual contact. HPV can also be transmitted from mother to baby during childbirth. Most people infected with HPV have no symptoms, but these viruses increase a woman's risk for cancer of the cervix. HPV infection is the most common sexually transmitted disease in the US. It is also the leading cause of abnormal PAP smears and pre-cancerous changes of the cervix in women. There is no cure for HPV infection, although anti-viral medications can reduce outbreaks and topical preparations can speed healing. Once contracted, the virus can stay with a person for life.
Condyloma latum:  A manifestation of the secondary stage of syphilis that takes the form of broad flat wartlike growths in moist creased areas, as around the anus and external genitalia.
Condyloma subcutaneum (Molluscum contagiosum):   Wartlike growths around the anus and genitals caused by a virus. Molluscum contagiosum is a contagious disease of the skin marked by the occurrence of soft rounded tumors of the skin caused by the growth of a virus belonging to the family Poxviridae. The disease is characterized by the appearance of few to numerous small, pearly, umbilicated downgrowths (the condyloma subcutaneum).
Cone dystrophy:  A disease of the cones, the specialized light-sensitive cells that act as photoreceptors in the retina of the eye, providing sharp central vision and color vision. The cone dystrophies are a form of genetic macular degeneration characterized by progressive deterioration of the cones that leads to the distinctive triad of loss of color vision, photophobia, and reduced central vision.
Cones:  A type of specialized light-sensitive cells (photoreceptors) in the retina of the eye that provide sharp central vision and color vision. By contrast, the rods are the retinal photoreceptors that provide side vision and the ability to see objects in dim light (night vision).
Conformal radiation therapy:  A procedure that uses computers to create a 3-dimensional picture of the tumor in order to target the tumor as accurately as possible and give it the highest possible dose of radiation while sparing normal tissue as much as possible. It is also known as 3-D or conformational radiation therapy.
Congenital:  Present at birth. A condition that is congenital is one that is present at birth. There are numerous uses of "congenital" in medicine. There are, for example, congenital abnormalities. Congenital does not mean genetic. Something that is congenital may or may not be genetic (inherited). For example, congenital syphilis is present at birth but is not genetic.
Congenital achromatopsia:  An hereditary disorder of vision characterized by a lack of cone vision (sight provided by the cone photoreceptors in the retina). People with achromatopsia (achromats) are completely or almost completely colorblind. They have poor visual acuity, and their eyes do not adapt normally to higher levels of illumination and are very light sensitive (photophobic). At higher levels of illumination, the vision of achromats decreases unless they make use of tinted lenses. In moderately bright indoor spaces or outdoors just after dawn or just before dusk, some achromats adapt to their reduced level of visual functioning without resorting to tinted lenses, by using visual strategies such as blinking, squinting, or positioning themselves in relation to the light source. Others routinely wear medium tinted lenses in such settings. In full sunlight outdoors or in very bright indoor spaces, almost all achromats use very dark tinted lenses to have a reasonable amount of vision, since their retinas do not possess the photoreceptors needed for seeing well in such settings. In normal eyes there are some 6 million cone photoreceptors that are located mainly in the center of the retina. Lacking cones, persons with achromatopsia have to rely on their rod photoreceptors for vision. In the normal eye there are some 100 million rod photoreceptors. Rods are located mostly at the periphery of the retina. Rods saturate at higher levels of illumination. They do not provide color vision or good detail vision.
Congenital anemia:  1. Anemia at birth. 2. Synonym for Rh incompatibility.
Congenital anomaly:  Something that is unusual or different at birth. A minor anomaly is defined as an unusual anatomic feature that is of no serious medical or cosmetic consequence to the patient. A minor anomaly of the feet might, for example, be curvature of the second toe so it overlaps the third toe a little. A major anomaly, by contrast, might be a cleft lip and palate, a birth defect of serious medical and cosmetic consequence to the child.
Congenital arthrogryposis:  Nonprogressive congenital contractures that develop before birth and are evident at birth (congenital). The contractures are characterized by reduced mobility of many (multiple) joints. Congenital arthrogryposis is also called arthrogryposis multiplex congenita (AMC). In AMC the range of motion of the joints in the arms and legs is usually limited or fixed. Joints affected may include the shoulders, elbows, wrists and fingers and the hips, knees, ankles, and feet - virtually any and all joints.
Congenital bilateral absence of vas deferens:  A condition in males when the tubes that carry sperm from the testes (the vas deferens) fail to develop normally. The testes usually develop and function normally and the men have normal sexual performance, but sperm cannot be transported through the male reproductive system. Men with congenital bilateral absence of vas deferens are therefore infertile (unable to conceive a child). This condition is responsible for 2 to 5% of all infertility in men.
Congenital central hypoventilation syndrome:  Failure from birth of central nervous system control over breathing while asleep. There are usually no breathing problems while awake. The involuntary (autonomic) control of respiration is impaired, but the voluntary control of ventilation which operates during waking hours is generally intact.
Congenital defect:  A birth defect.
Congenital hemolytic jaundice:  Known also as hereditary spherocytosis (HS), this is a genetic disorder of the red blood cell membrane clinically characterized by anemia, jaundice (yellowing) and splenomegaly (enlargement of the spleen). In HS the red cells are smaller, rounder, and more fragile than normal. The red cells have a spherical rather than the biconcave-disk shape of the normal red cell. These rotund red cells (spherocytes) are osmotically fragile and less flexible than normal red cells and tend to get trapped in narrow blood passages, particularly in the spleen, and there they break up (hemolyze) leading to hemolytic anemia. The clogging of the spleen with red cells almost invariably causes splenomegaly.
Congenital hip dislocation:  The abnormal formation of the hip joint in which the ball at the top of the thighbone (the femoral head) is not stable within the socket (the acetabulum). The ligaments of the hip joint may also be loose and stretched. The degree of instability or looseness varies. A baby born with this condition may have the ball of the hip loosely in the socket (subluxed) or the ball of the hip may be completely dislocated at birth. Untreated, the condition may cause legs of different lengths and a "duck-like" walk and lead to pain on walking and early osteoarthritis. There is a familial tendency. It usually affects the left hip and is more common in girls than boys, in first-born children and in babies born in the breech position. It is more common in Native Americans than in whites and is rarely seen in African-American children. One of the early signs that a baby has been born with a dislocated hip may be a clicking sound when the baby's legs are moved apart.
Congenital hypothyroidism:  See Cretinism.
Congenital lymphedema:  A condition present at birth in which excess fluid called lymph collects in tissues and causes swelling (edema) in them. Congenital lymphedema is due to a congenital malformation (that is, a birth defect) of the lymphatic system. Congenital lymphedema can be found associated with the Noonan and Turner syndromes and a number of forms of lymphedema are clearly due to genetic factors.
Congenital malformation:  A physical defect present in a baby at birth, irrespective of whether the defect is caused by a genetic factor or by prenatal events that are not genetic. In a malformation, the development of a structure is arrested, delayed, or misdirected early in embryonic life and the effect is permanent. Congenital malformations can involve many different organs including the brain, heart, lungs, liver, bones, and intestinal tract. These defects can occur for many reasons including inherited (genetic) conditions, toxic exposure of the fetus (for example, to alcohol), birth injury and, in many cases, for unknown reasons. All parents are at risk of having a baby with a birth defect, regardless of age, race, income or residence. In the US (and many other developed nations), 2-3% of babies are born with a major congenital malformation.
Congenital neutropenia, severe (SCN):  Children born with this condition lack neutrophils (a type of white blood cell that is important in fighting infection). These children suffer frequent infections from bacteria which in the past led to death in three-quarters of cases before 3 years of age. This disease is also known as severe congenital neutropenia (SCN).
Congenital ptosis of the eyelids:  Drooping of the upper eyelids at birth. The lids may droop only slightly or they may cover the pupils and restrict or even block vision. Moderate or severe ptosis calls for treatment to permit normal vision development. If not corrected, amblyopia ("lazy eye") may develop which can lead to permanently poor vision. Ptosis at birth is often caused by poor development of the levator muscle (levator palpebra superioris) which lifts the eyelid. Children with ptosis may tip their heads back into a chin-up position to see underneath the eyelids or raise their eyebrows in an attempt to lift up the lids. Congenital ptosis rarely improves with time. Mild or moderate ptosis usually does not require surgery early in life. Treatment is usually surgery to tighten the eyelid-lifting muscles, the levators. If the levator is very weak, the lid can be attached or suspended from under the eyebrow so that the forehead muscles can do the lifting. Even after surgery, focusing problems can develop as the eyes grow and change shape. All children with ptosis, whether they have had surgery or not, should therefore be followed by an ophthalmologist.
Congenital rubella syndrome:  The constellation of abnormalities caused by infection with the rubella (German measles) virus before birth. The syndrome is characterized by multiple congenital malformations (birth defects) and mental retardation. The individual features of the syndrome include growth retardation, microcephaly (abnormally small head), cataracts, glaucoma, microphthalmia (abnormally small eyes), cardiovascular malformations, hearing loss, and mental retardation. Deafness is common. After birth the child may develop diabetes due to gradual destruction of the pancreas by the rubella virus. The child has a 50% risk of being born with the congenital rubella if the mother is infected with rubella in the first trimester (the first third) of pregnancy. Risks still exist with infection in the second trimester.
Congenital stationary night blindness:  An inherited eye disorder that is not progressive ("stationary") and principally affects the rod photoreceptors in the retina, impairing night vision. There may also be moderate to high myopia (near-sightedness). Under good lighting conditions, there is usually no visual deficit. The disorder is diagnosed by electroretinography. There are several different types of the disorder which are inherited in an autosomal dominant, autosomal recessive, or X-linked recessive manner. The X-linked type affects almost exclusively males and accounts for the predominance of males with congenital stationary night blindness. Children with the disorder may have a fear of the dark.
Congenital torticollis:  A deformity of the neck that is evident at birth. It is due to shortening of the neck muscles. Congenital torticollis tilts the head to the side on which the neck muscles are shortened so that the chin points to the other side. The neck muscle that is shortened are the sternocleidomastoid and it is principally supplied by the spinal accessory nerve. "Torticollis" = "twisted neck."
Congenital vaccinia:  Infection of the fetus in the last trimester of pregnancy due to bloodborne dissemination of the vaccinia virus in the pregnant woman after she has received a smallpox vaccination. The affected infant is often premature. The skin lesions in the newborn infant are like a fresh vaccination but often confluent and extensive. Death almost always occurs before birth or shortly thereafter. To prevent this dire disorder, it is recommended that pregnant women not be vaccinated unless special circumstances may call for it (e.g., they have been exposed to a smallpox patient or are a household member of a smallpox case).
Congestive heart failure:  Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. There are many causes of congestive heart failure including: (1) coronary artery disease leading to heart attacks and heart muscle weakness, (2) primary heart muscle weakness from viral infections or toxins such as prolonged alcohol exposure, (3) heart valve disease causing heart muscle weakness due to too much leaking of blood or heart muscle stiffness from a blocked valve, and (4) hypertension (high blood pressure). Rarer causes include hyperthyroidism (high thyroid hormone), vitamin deficiency, and excess amphetamine ("speed") use. The aim of therapy is to improve the pumping function of the heart. General treatment includes salt restriction, diuretics (to get rid of excess fluid), digoxin (to strengthen the heart), and other medications. A drug called spironolactone has been found to be a major help in treating congestive heart failure Its beneficial effects are additive to those from ACE inhibitors, another class of drugs commonly relied on in treating heart failure. A pacemaker-like device is also now available to treat heart failure. The implantable device delivers synchronized electrical stimulation to three chambers of the heart, enabling the heart to pump blood more efficiently throughout the body.
Conization:  Surgery to remove a cone-shaped piece of tissue from the cervix and cervical canal. Conization may be used to diagnose or treat a cervical condition. Also called cone biopsy.
Conjoined twin:  Identical (monozygotic) twins that did not separate fully from one another but are still partially united. Due to the incomplete division of one fertilized ovum. Conjoined twins are popularly known as Siamese twins after Chang and Eng (1811-1874), the celebrated conjoined Chinese twins born in Siam (Thailand).
Conjugated linoleic acid (CLA):  A supplement that has been promoted as an aid to weight loss and muscle building and as a deterrent to heart disease, diabetes and cancer. CLA is an unsaturated fatty acid in the milk and meat of cows, sheep and goats. CLA occurs in about 20 different chemical configurations called isomers, each tending to have different effects on the body.
Conjunctiva:  A thin clear moist membrane that coats the inner surfaces of the eyelids and the outer surface of the eye. The section of the conjunctiva that coats the inner aspect of the eyelids is called the palpebral conjunctiva while that covering the outer surface of the eye is called the ocular or bulbar conjunctiva.
Conjunctival fornix:  The fornix of the conjunctivae refers to loose arching folds connecting the conjunctival membrane lining the inside of the eyelid with the conjunctival membrane covering the eyeball. In anatomy, a vaultlike or arched structure. "Fornix" is the Latin word for "vault or arch."
Conjunctivitis:  Inflammation of the conjunctiva, the membrane on the inner part of the eyelids and the membrane covering the white of the eye. The conjunctival membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants and toxic agents. Viral and bacterial forms of conjunctivitis are common in childhood. Conjunctivitis is also called pink eye and red eye. The leading cause of a red eye is virus infection.
Conn syndrome:  Overproduction of the hormone aldosterone (pronounced al-do-ster-one) by a tumor that contains tissue resembling that normally present in the outer portion (cortex) of the adrenal gland. The excess aldosterone results in a low potassium level (hypokalemia), underacidity of the body (alkalosis), muscle weakness, excessive thirst (polydipsia), excessive urination (polyuria), and high blood pressure (hypertension). Also called primary aldosteronism or primary hyperaldosteronism. The syndrome is named after the American physician Jerome W. Conn (1907-1981) who almost single-handedly defined the syndrome of aldosterone excess.
Connective tissue:  A material made up of fibers forming a framework and support structure for body tissues and organs. Connective tissue surrounds many organs. Cartilage and bone are specialized forms of connective tissue. All connective tissue is derived from the mesoderm, the middle germ cell layer in the embryo.
Connective tissue disease:  A disease (autoimmune or otherwise) that attacks the collagen or other components of connective tissue, such as lupus.
Connexin:  A subunit of connexon, a protein that forms a gap junction, a channel that permits ions and small molecules to move between adjacent cells. The connexins are important to intercellular communication. Historically, gap junctions were first characterized by EM (electron microscopy). They appeared to be specialized structures in the plasma membranes of cells in contact with one another. These specialized structures were then shown to consist of cell-to-cell channels. In analyzing the channels from different tissues, the components of these channels were found to differ. These components were named connexins. Mutations in the connexins are responsible for a diversity of diseases, including deafness and skin disorders. At least four connexins are known to be expressed in the ear. In many populations, mutations of the connexins are the most frequent cause of autosomal recessive deafness. Connexin mutations are also responsible for several forms of inherited keratoderma - a skin disorder characterized by thickened (hyperkeratotic) skin on the palms and soles - as well as peripheral neuropathy and cataract formation.
Connexon:  A special type of protein composed of an assembly of six subunits that are called connexins. A connexon of one cell is joined to that of an adjacent cell to form an intercellular channel consisting of 12 connexin subunits. Clusters of intercellular channels are known as a gap junction because of the minute extracellular "gap" that separates the apposed plasma membranes. Each intercellular channel provides an axial channel that interconnects the cytoplasm of the apposed cells directly and permits the passage of ions and other small molecules between adjacent cells.
Conor and Bruch disease:  African tick typhus, one of the tick-borne rickettsial diseases of the eastern hemisphere similar to Rocky Mountain spotted fever but less severe. Characteristic features include fever, a small ulcer (tache noire) at the site of the tick bite, swollen glands nearby (satellite lymphadenopathy), and a red raised (maculopapular) rash.
Conotoxin:  A toxin made by cone snails (Conidae), also called cone shells, which are fish-eating snails that inhabit tropical coral reefs, mangroves and associated habitats. Each of the 500 species of cone snail produces roughly 50 to 100 distinct conotoxins which they use to immobilize prey. These toxins are selective in their receptor binding sites. Conotoxins have been used to characterize receptors in heart muscle, skeletal muscle and brain. Calcium, potassium, and sodium ion channels have also been characterized using conotoxins.
Consanguinity:  Blood relationship because of common ancestry. Everyone carries rare recessive alleles, rare genes that are generally innocuous in the heterozygous state (matching chromosomes, one from father, one from mother) but that in the company of another gene of the same type are capable of causing an autosomal recessive disease. We are all reservoirs for genetic disease. First cousins, for example, share a set of grandparents. So for any particular allele (gene) in the father, the chance that the mother inherited the same allele from the same source is 1/8. Further, for any gene the father passes to his child, the chance is 1/8 that the mother has the same gene and ½ that she transmits that gene to the child so 1/8 X ½ = 1/16. Thus, a first-cousin marriage has a coefficient of inbreeding of 1/16. The added risks for first cousins depend not only upon this coefficient of inbreeding but also upon their genetic family histories and, in some cases, upon test results (for example, for beta thalassemia for first cousins of Italian descent). However, there are always added risks from the mating of closely related persons and those risks are not negligible.
Conservative mutation:  A change in a DNA or RNA sequence that leads to the replacement of one amino acid with a biochemically similar one. It is conservative in the sense that it is not a radical change that might, for example, stop all protein production.
Consolidation therapy:  Cancer treatment given after induction therapy to consolidate the gains obtained, further reduce the number of cancer cells and achieve a complete remission. Often just called consolidation. The overall sequence of therapy may be induction, consolidation, and maintenance therapy. Induction therapy is the initial step toward reducing the number of cancer cells. Consolidation is designed to further diminish the number of cancer cells and achieve a complete remission. Maintenance is given to maintain the remission and prevent a relapse.
Constipation:  Infrequent (and frequently incomplete) bowel movements. The opposite of diarrhea, constipation is commonly caused by irritable bowel syndrome, diverticulosis, and medications. Constipation can paradoxically be caused by overuse of laxatives. Colon cancer can narrow the colon and thereby cause constipation. Barring a condition such as cancer, high-fiber diets can frequently relieve the constipation.
Constituitonal Thrombopathy (Von Willebrand disease):   An inherited bleeding disorder in which a clotting protein called von Willebrand factor is deficient or defective. Von Willebrand factor is made by cells lining the wall of blood vessels. When vessels are damaged, platelets normally clump at the site of the injury. Von Willebrand factor acts as glue to help the platelets clump. Von Willebrand factor is also a carrier of clotting factor VIII, another protein that helps the blood to clot. Von Willebrand disease is the most common inherited bleeding disorder. It occurs in about 1 in every 100 to 1,000 people. There are three major types of von Willebrand disease: Type 1 -- the mildest and most common form of the disease. There is a low level of von Willebrand factor. Levels of factor VIII may also be lower than normal. Type 2 -- a mild-to-moderate form of the disease. Von Willebrand factor does not work as it should. Type 2 is divided into types 2A, 2B, and 2C. Type 3: -- the most severe form of the disease and very rare. Von Willebrand factor is absent and factor VIII is low. All three types of von Willebrand disease affect both males and females.
Constraint-induced movement therapy:  A form of intensive physical therapy aimed at reorganizing and reprogramming the brain after a stroke, a traumatic brain injury, or spinal cord damage.
Consumption:  An old and once common term for wasting away of the body, particularly from pulmonary tuberculosis (TB). Other old TB terms include the King's evil or scrofula (TB of the lymph nodes in the neck) and Pott's disease (TB of the spine).
Contact dermatitis:  A skin condition caused by contact between skin and some substance. Includes irritant contact dermatitis (a rash brought on purely by repeated irritation from a substance such as water causing "dish pan hands") and allergic contact dermatitis (involving a specific sensitivity or allergy to a specific substance such as poison ivy).
Contact eczema:  A localized reaction that includes redness, itching, and burning where the skin has come into contact with an allergen (an allergy-causing substance) or with an irritant such as an acid, a cleaning agent or another chemical.
Contact healing:  Another name for the alternative medicine practice of laying on of hands. See: Laying on of hands. See also: Therapeutic touch.
Contig:  Contiguous sequence of DNA created by assembling overlapping sequenced fragments of a chromosome. A group of clones representing overlapping regions of the genome. A contig is a chromosome map showing the locations of those regions of a chromosome where contiguous DNA segments overlap. Contig maps are important because they provide the ability to study a complete, and often large, segment of the genome by examining a series of overlapping clones which then provide an unbroken succession of information about that region.
Contig map:  A map depicting the relative order of a linked library of small overlapping clones representing a complete chromosome segment.
Contiguous gene syndrome:  A disorder due to deletion of multiple gene loci that are adjacent to one another. Contiguous gene syndromes are characterized by multiple, apparently unrelated, clinical features caused by deletion of the multiple adjacent genes. Each of the individual genes within a contiguous region, when mutated, gives rise to a distinct feature. An example of a contiguous gene syndrome is Angelman syndrome. It is due to the loss of a series of genes from a region of chromosome 15 termed 15q13-15. (The syndrome is characterized by four cardinal features: severe developmental delay or mental retardation, severe speech impairment, gait ataxia (wobbliness) and/or tremulousness of the limbs; and a unique behavior with an inappropriate happy demeanor that includes frequent laughing, smiling, and excitability. In addition, microcephaly (abnormally small head) and seizures are common.) In Angelman syndrome the genes that were lost prove always to have been from the mother. If they were from the father, an entirely different contiguous gene syndrome results called Prader-Willi syndrome.
Continuous passive motion machine:  A machine used to help rehabilitate a limb (an arm or leg). The continuous passive motion (CPM) machine is attached to, for example, a knee that has had surgery. The CPM machine then constantly moves the knee through a range of motion for a period of time while the patient relaxes.
Contraception, implantable progestin:  Implantable progestin in the form of Norplant was approved by the U.S. Food and Drug Administration (FDA) for contraception in 1990 and the newer Norplant 2 was approved by the FDA in 1996. Made up of matchstick-sized rubber rods, this type of contraceptive is surgically implanted under the skin of the woman's upper arm, where it steadily releases a contraceptive substance (a progestin called levonorgestrel). The six-rod Norplant provides protection for up to 5 years (or until it is removed), while the two-rod Norplant 2 protects for up to 3 years. Norplant failures are rare but are higher with increased body weight (in heavier women). Some women may experience inflammation or infection at the site of the implant. Other side effects include menstrual cycle changes, weight gain, and breast tenderness. This is not recommended by this doctor due to risks similar to "the pill."
Contraceptive device, intrauterine (IUD):  A device ; inserted into the uterus (womb) to prevent conception (pregnancy). The IUD can be a coil, loop, triangle, or T in shape made of plastic or metal. An IUD is ; inserted into the uterus by a health-care professional. Of two types of IUDs approved in the U.S., one can remain in place for 10 years, while the other must be replaced every year. How IUDs prevent pregnancy is not entirely clear. They seem to prevent sperm and eggs from meeting by either immobilizing the sperm on their way to the fallopian tubes or by changing the uterine lining so the fertilized egg cannot implant in it. IUDs have one of the lowest failure rates of any contraceptive method. " In the population for which the IUD is appropriate -- for those in a mutually monogamous, stable relationship who are not at a high risk of infection -- the IUD is considered a safe and effective method of contraception. However, the IUD's image suffered when the Dalkon Shield IUD, which was associated with a high incidence of pelvic infections and infertility and some deaths, was taken off the market in 1975. Today, serious complication from IUDs are rare, although IUD users may be at increased risk of developing pelvic inflammatory disease. Other side effects can include perforation of the uterus, abnormal bleeding, and cramps. Complications occur most often during and immediately after insertion. This is in part based on information from the U.S. Food and Drug Administration (the FDA), the same outfit that approves drugs which kill over 100,000 Americans each year, so take it all with a grain of salt.
Contraceptive, combined oral:  Commonly called "the pill," combined oral contraceptives are the most commonly used form of reversible birth control in the United States. This form of birth control suppresses ovulation (the monthly release of an egg from the ovaries) by the combined actions of the hormones estrogen and progestin. If a woman remembers to take the pill every day as directed, she has an extremely low chance of becoming pregnant in a year. But the pill's effectiveness may be reduced if the woman is taking some medications, such as certain antibiotics. Besides preventing pregnancy, the pill can make periods more regular. Birth control pills carry some risks. Current low-dose pills have fewer risks associated with them than earlier versions. But women who smoke, especially those over 35, and women with certain medical conditions such as a history of blood clots or breast or endometrial cancer, may be advised against taking the pill. The pill may also contribute to cardiovascular disease, including high blood pressure, blood clots, and blockage of the arteries. One of the biggest questions has been whether the pill increases the risk of breast cancer in past and current pill users. The side effects of the pill include nausea, headache, breast tenderness, weight gain, irregular bleeding, and depression. This doctors advice: if you are going to use contraception, find a method other than "the pill."
Contraceptive, diaphragm:  A barrier method of contraception that is available by prescription only and must be sized by a health professional to achieve a proper fit. The diaphragm has a dual mechanism to prevent a pregnancy. A dome-shaped rubber disk with a flexible rim covers the cervix so sperm cannot reach the uterus and a spermicide applied within the diaphragm before insertion kills sperm. A diaphragm protects against conception for six hours. For intercourse after the six-hour period, or for repeated intercourse within this period, fresh spermicide should be placed in the vagina with the diaphragm still in place. The diaphragm should be left in place for at least six hours after the last intercourse. A diaphragm should not be left in place for more than a total of 24 hours because of the risk of toxic shock syndrome (TSS), a rare but potentially fatal condition. Symptoms of TSS include sudden fever, stomach upset, a sunburn-like rash, and a drop in blood pressure.
Contraceptive, injectable progestin:  Injectable progestin (Depo-Provera) was approved by the U.S. Food and Drug Administration (FDA) for contraception in 1992. It is injected by a health professional into the woman's buttocks or arm muscle every three months. Depo-Provera prevents pregnancy in three ways: It inhibits ovulation, changes the cervical mucus to help prevent sperm from reaching the egg, and changes the uterine lining to prevent the fertilized egg from implanting in the uterus. The progestin injection is extremely effective in preventing pregnancy. Side effects can include irregular or missed periods, weight gain, and breast tenderness. Recommendation: forget it.
Contraceptive, minipill:  A form of oral contraceptive taken daily, like combined oral contraceptives (the "pill"), but containing only the hormone progestin (synthetic, not natural) and no estrogen. The minipill works by reducing and thickening cervical mucus to prevent sperm from reaching the egg. It also keeps the uterine lining from thickening, which prevents a fertilized egg from implanting in the uterus. The minipill is slightly less effective in preventing conception than the pill. The minipill can decrease menstrual bleeding and cramps as well. Because the minipill contains no estrogen, it does not present the risk of blood clots associated with estrogen in combined pills. The minipill is a useful option for women who cannot take estrogen because they are breast-feeding or because estrogen-containing products cause them to have severe headaches or high blood pressure. The side effects of the minipill include menstrual cycle changes, weight gain, and breast tenderness.
Contraction:  The tightening and shortening of a muscle.
Contraction, uterine:  The tightening and shortening of the uterine muscles. During labor, contractions accomplish two things: (1) they cause the cervix to thin and dilate (open); and (2) they aid the baby to descend into the birth canal.
Contractions, Braxton Hicks:  Irregular contractions of the womb (the uterus) occurring towards the middle of pregnancy in the first pregnancy and, earlier and more intensely, in subsequent pregnancies. These contractions tend to occur during physical activity. The uterus tightens for 30 to 60 seconds beginning at the top of the uterus; and the contraction gradually spreads downward before relaxing. Although said to be painless, Braxton Hicks contractions may be quite uncomfortable and sometimes difficult to distinguish from the contractions of true labor. Named for Dr. John Braxton Hicks (1823-1897), a British gynecologist.
Contraindication:  A condition which makes a particular treatment or procedure inadvisable. A contraindication may be absolute or relative. An absolute contraindication is a situation which makes a particular treatment or procedure absolutely inadvisable. In a baby, for example, aspirin is absolutely contraindicated because of the danger that aspirin will cause Reye syndrome. A relative contraindication is a condition which makes a particular treatment or procedure somewhat inadvisable but does not rule it out. For example, X-rays in pregnancy are relatively contraindicated (because of concern for the developing fetus) unless the X-rays are absolutely necessary.
Contralateral:  On the other side. The contralateral breast is the breast on the other side. A stroke affecting the right side of the brain may cause contralateral paralysis, affecting the left arm and leg. The opposite of contralateral is ipsilateral which refers to the same side.
Contrast:  Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.
Contrast nephropathy:  A form of acute renal failure that starts soon after administration of contrast media (dye) for X-rays. The disorder usually runs a benign course and only rarely requires recourse to dialysis.
Contusion:  Another name for a bruise. What is a bruise ? A bruise, or contusion, is caused when blood vessels are damaged or broken as the result of a blow to the skin (be it bumping against something or hitting yourself with a hammer). The raised area of a bump or bruise results from blood leaking from these injured blood vessels into the tissues as well as from the body's response to the injury. A purplish, flat bruise that occurs when blood leaks out into the top layers of skin is referred to as an ecchymosis.
Conventional medicine:  Medicine as practiced by most holders of M.D. (medical doctor) or D.O. (doctor of osteopathy) degrees and by their allied health professionals, such as physical therapists, psychologists, and registered nurses. Other terms for conventional medicine include allopathy and allopathic medicine; Western medicine, mainstream medicine, orthodox medicine, and regular medicine.
COPD:   Chronic obstructive pulmonary disease. Any disorder that persistently obstructs bronchial airflow. COPD mainly involves two related diseases - chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time. Asthma is also a pulmonary disease in which there is obstruction to the flow of air out of the lungs, but the obstruction is usually reversible and between attacks of asthma the flow of air through the airways is usually good. COPD is also called chronic obstructive lung disease (COLD).
Coprolalia:  The excessive and uncontrollable use of foul or obscene language, including words related to feces (bowel waste). Coprolalia is a typical symptom of Tourette syndrome, a condition that has its onset in childhood and is characterized by compulsive arm movements, facial tics, grunting, groaning and shouting. Aside from coprolalia, there is often echolalia, the involuntary parrot-like repetition (echoing) of a word or sentence just spoken by another person. Persons with Tourette syndrome do not usually curse out of anger or displeasure but out of uncontrollable compulsion. They cannot help themselves. (The disease is also called Gilles de la Tourette syndrome.) Coprolalia can upon occasion also be a symptom of schizophrenia, a severe psychiatric disorder of thought in which the sufferer loses touch with reality, withdraws from social activity and exhibits bizarre behavior. The schizophrenic may curse for no apparent reason. (There is no known relationship between Tourette syndrome and schizophrenia.)
CoQ10:  A compound needed for the proper functioning of an enzyme, a protein that speeds up the rate at which chemical reactions take place in the body. Coenzyme Q10 is used to produce energy to fuel cell growth and maintenance. Coenzyme Q10 is thought to improve the function of mitochondria, the "powerhouses" that produce energy in cells. Coenzyme Q10 is also an antioxidant, a substance that protects cells from highly reactive chemicals called free radicals that can damage cells and their DNA. The highest amounts of coenzyme Q10 are in the heart, liver, kidneys, and pancreas and the lowest amounts are in the lungs. The levels of coenzyme Q10 normally decline with age. Coenzyme Q10 may have a place in the treatment of some neurological diseases. A placebo-controlled clinical trial of coenzyme Q10 suggested that it can slow the rate of deterioration in patients with early-stage Parkinson disease. The consumption of up to 800 mg/day of coenzyme Q10 was well-tolerated. The trial was funded by NIH and appeared in the Archives of Neurology in 2002. Coenzyme Q10 has also been of interest for cancer therapy. However, no report of a randomized clinical trial of coenzyme Q10 as a treatment for cancer had been published in a peer-reviewed, scientific journal as of July, 2004. Coenzyme Q10 is sold in the US as a dietary supplement.The Q and the 10 in coenzyme Q10 refer to parts of the compound’s chemical structure. It is also known as CoenzymeQ10, Q10, vitamin Q10, and ubiquinone.
Cor:  The Latin word for the heart.
Cor biloculare:  A two-chambered heart. Cor biloculare is due to failure of development of the walls that normally separate the two atria (interatrial septum) and the two ventricles (interventricular septum).
Cor pulmonale:  Heart disease that results from abnormally high resistance to the passage of blood through the lungs; it often leads to right heart failure.
Cord:  1. In anatomy, a long ropelike structure. 2. Short for the spinal cord or the umbilical cord.
Cordectomy:  1. Surgical removal of a vocal cord. 2. Surgical removal of part of the spinal cord.
Corn:  A small calloused area of skin caused by local pressure irritating tissue over a bony prominence. Corns most commonly occur over a toe where they form what is referred to as a hard corn. Between the toes, pressure can form a soft corn of macerated skin which often turns yellow. The word corn comes from the Latin "cornu" meaning horn or hoof. A corn on the toe is also called a clavus.
Cornea:  The clear front window of the eye that transmits and focuses light into the eye.
Corneal abrasion:  A scratch or scrape on the cornea.
Corneal dystrophy:  A condition in which one or more parts of the cornea lose their normal clarity due to a buildup of cloudy material. There are over 20 corneal dystrophies that affect all parts of the cornea.
Corneal ring, intrastromal:  A plastic ring designed to be implanted in the cornea, the transparent structure in the front of the eye. The aim of the corneal ring implant is to flatten the cornea and in so doing to correct or reduce the degree of myopia (nearsightedness). The ring is called an intrastromal ring because it is placed in the corneal stroma, the middle one of the five layers that make up the cornea.
Corneal transplant:  The replacement of the clear window on the front of the eye (cornea) by a healthy cornea. The procedure is typically done under local anesthesia in an outpatient setting. Transplantation of the cornea may be indicated in cases of severe scarring of the cornea by injury or infection (as with corneal ulcers) and in genetic disorders such as keratoconus (inherited corneal thinning with visual distortion) and Fuch's dystrophy (inherited corneal clouding with visual loss). The very limited blood supply of the cornea greatly reduces the risk of transplant rejection. Corneal transplants generally function effectively for many years.
Coronal plane:  A imaginary anatomical slice through the body in a vertical plane from head to foot and parallel to the shoulders.
Coronary angiography:  A method for evaluating and defining coronary artery disease (CAD). Coronary angiography is used to identify the location CAD. A small catheter (a thin hollow tube with a diameter of 2-3 mm) is inserted through the skin into an artery in the groin or the arm. Guided with the assistance of a fluoroscope (a special x-ray viewing instrument), the catheter is then advanced to the opening of the coronary arteries, the blood vessels supplying blood to the heart. Next, a small amount of radiographic contrast (a solution containing iodine, which is easily visualized with x-ray images) is injected into each coronary artery. The images that are produced are called the angiogram. Angiographic images accurately reveal the extent and severity of all coronary arterial blockages. Coronary angiography is performed with the use of local anesthesia and intravenous sedation, and is generally not terribly uncomfortable. The procedure takes approximately 20-30 minutes. After the procedure, the catheter is removed and the artery in the leg or arm is sutured, "sealed," or treated with manual compression to prevent bleeding. There is a small risk of serious complications from coronary angiography, as it is an "invasive" test, but in the hands of an experienced physician this risk is about one per cent of cases where death occurs. While the party line is that angiography is an accurate way to evaluate the degree of blockage, double-blind cross-over studies have demonstrated little agreement between experienced radiologists as to the degree of blockage in any given case. The fact seems to be that it is a rough guess made by "eye-balling" the fluoroscopy.
Coronary arteries:  The vessels that supply the heart muscle with blood rich in oxygen. They are called the coronary arteries because they encircle the heart in the manner of a crown. The word "coronary" comes from the Latin "corona" and Greek "koron" meaning crown. Like other arteries, the coronaries may be subject to arteriosclerosis (hardening of the arteries). There are a number of coronary arteries. Those most often bypassed today include the right coronary artery, the posterior descending coronary artery, the left main coronary artery, the left anterior descending coronary artery and the left circumflex coronary artery. Plaques obstructing the coronary arteries may also be treated by balloon angioplasty, stents, and other techniques. However we now have the ability to safely reduce plaque (atherosclerosis) with a formula developed in Europe which includes intravenous phosphytidal choline (known as Plaquex in Europe) and soften hardened walls of arteries (arteriosclerosis) with intravenous EDTA chelation therapy. Surgery should now be considered an absolute last resort for cases so advanced there is no other solution, however it is not so considered by surgeons and hospitals - which may have something to do with how lucrative it is for doctors and hospitals to do these procedures. This condition prevales despite a mortality rate of up to 5% for bypass surgery.
Coronary artery brachytherapy:  Local radiation treatment within an artery to the heart. Coronary artery brachytherapy has been used to reduce the recurrence of blockage (obstruction) of a coronary artery after successful treatment of a blockage of a stent. (A stent is a tubular structure that is implanted inside of a coronary artery to keep it open, thereby preventing a heart attack.) The radiation from coronary artery brachytherapy is believed to prevent cells from reproducing to cause blockage of the blood vessel (coronary artery). Recurrent blockage after placement of a coronary artery stent has been reported to occur in 20 to 30 percent of patients.
Coronary artery bypass graft:  Abbreviated CABG. A form of bypass surgery that can create new routes around narrowed and blocked coronary arteries, permitting increased blood flow to deliver oxygen and nutrients to the heart muscle. Coronary artery bypass graft is an option for selected groups of patients with significant narrowings and blockages of the heart arteries. The bypass graft for a CABG can be a vein from the leg or an inner chest-wall artery. CABG surgery is one of the most commonly performed major operations. Coronary artery disease develops because of plaque in arteries (atherosclerosis) that supply blood to the heart muscle. Diagnostic tests prior to (and after) CABG include the electrocardiogram (EKG), stress test, echocardiogram, and coronary angiography. Large scale studies have shown that this procedure has no effect on mortality from heart disease compared to non-invasive therapies, yet hundreds of thousands are performed annually in the U.S. for financial reasons.
Coronary artery disease:  A major cause of illness and death, coronary artery disease (CAD) begins with inflammation and only later involves cholesterol deposits. Cholesterol is irrelevant until the inflammatory event occurs, yet thanks to what has been called the "Great Cholesterol Hoax," the public and even doctors are mistakenly focused on cholesterol levels instead of preventing intravascular inflammation. Once plaque exists in the coronary arteries they can cause a tiny clot to form due to turbulence of blood flow around them whihc damages blood cells and this can then obstruct the flow of blood to the heart muscle producing symptoms and signs of CAD that may include: chest pain (angina pectoris) from inadequate blood flow to the heart; heart attack (acute myocardial infarction), from the sudden total blockage of a coronary artery; or sudden death, due to a fatal disturbance of the heart rhythm.
Coronary artery spasm:  A spasm (a sudden constriction) of one of the coronary arteries depriving the (myocardium (the heart muscle) of blood and oxygen. This can cause chest pain referred to as variant (or Prinzmetal's) angina. Coronary artery spasm can be triggered by emotional stress, medicines, street drugs (such as cocaine) or exposure to cold. Treatments include beta-blocker medications and, classically, nitroglycerin is prescribed to permit the coronary arteries to open up (dilate). Illicit drug use should be discontinued and stress reduced, if possible.
Coronary insufficiency:  Insufficient blood flow through one or more coronary arteries.
Coronavirus:  One of a group of RNA viruses, so named because they look like a corona or halo when viewed under the electron microscope. The corona or halo is due to an array of surface projections on the viral envelope. The coronavirus genome is a single strand of RNA 32 kilobases long and is the largest known RNA virus genome. Coronaviruses are also unusual in that they have the highest known frequency of recombination of any positive-strand RNA virus, promiscuously combining genetic information from different sources. Coronaviruses are ubiquitous. They are the second leading cause of the common cold (after the rhinoviruses). Members of the coronavirus family cause major illnesses among animals, including hepatitis (inflammation of the liver) in mice and gastroenteritis (inflammation of the digestive system) in pigs, and respiratory infections (in birds). Soon after the start of the outbreak of SARS (severe acute respiratory syndrome) in 2002-2003, a coronavirus came under suspicion as one of the leading suspects. A new coronavirus was, in fact, discovered to be the agent responsible for SARS.
Corpora cavernosa:  Two chambers in the penis which run the length of the organ and are filled with spongy tissue. Blood flows in and fills the open spaces in the spongy tissue to create an erection.
Corporeal:  Pertaining to the body of an organ or the entire body. The term also serves as a suffix, as in intracorporeal or extracorporeal. From the Latin corpus meaning body and ultimately from an Indo-European word that is also the ancestor of the term corpse.
Corpse:  A dead body. The term corpse is more often used in mystery stories than in medicine which, for obscure reasons, prefers the term cadaver. Corpse entered the English language in the 14th century. It came from the Latin corpus meaning body and, ultimately, from an Indo-European word that is also the ancestor of English corpus and corporeal (and corset).
Corpus:  The body of the uterus (womb).
Corpus callosotomy:  An operation in which all or part of this structure is cut, disabling communication between the hemispheres and preventing the spread of seizures from one side of the brain to the other. This procedure, sometimes called split-brain surgery, is for patients with extreme forms of uncontrollable epilepsy who have intense seizures that can lead to violent falls and potentially serious injury.
Corpus callosum:  A band of nerve fibers connecting the two halves (hemispheres) of the brain.
Corpus luteum:  the hormone producing structure left behind by an egg after it is extruded from the ovary. The corpus luteum produces progesterone which readies the uterus for the implantation of a fertilized egg. The term means, literally, "body white," referring to its appearance.
Corrigan pulse:  A pulse that is full and then suddenly collapses. Named for the Irish physician Dominic John Corrigan (1802-80) who described it in patients with aortic regurgitation due to a leaky aortic valve in the heart. Also called a water hammer pulse.
Cortex:  The outer portion of an organ. The outer portion of the adrenal gland is called the adrenal cortex; the outer portion of the cerebrum is the cerebral cortex (a key part of the brain); the outer part of the kidney is the renal cortex (it lies just beneath the capsule surrounding the kidney); etc. The cortex is in contrast to the inner portion of the organ which is called the medulla. Thus, there is the adrenal medulla; the medulla oblongata of the brain; the renal medulla; etc. The word "cortex" is Latin for the bark of a tree. The plural of cortex is cortices. The adjective is cortical.
Cortical:  Having to do with the cortex, the outer portion of an organ.
Cortical blindness:  Blindness due to loss or injury to the visual cortex, that section of the cerebral cortex responsible for vision, as through a stroke or traumatic brain damage. In early life the cortex is "taught" by the eyes how to see. If one or both eyes are non-functional in the first years of life, the critical time for teaching the occipital cortex to see, then blindness ensues even if later the eye is restored to normal. Even an eyelid condition, such as a large hemangioma, forces the eyelid shut for extended periods, blindness is then permanent on the side where that occurred.
Corticosteroid:  Any of the steroid hormones made by the cortex (outer layer) of the adrenal gland. Cortisol is a corticosteroid.
Corticosteroid allergy:  A delayed allergic reaction to corticosteroid (drugs similar to cortisone). This occurs in 1-4% of people who use corticosteroids for asthma or other allergic diseases. A positive patch test to a corticosteroid means the patient cannot use that particular steroid. Although cross allergy between corticosteroids is common, such patients usually can tolerate another corticosteroid.
Corticotropin-releasing hormone:  A hormone made by the hypothalamus that stimulates the release of corticotropin by the anterior pituitary gland. Corticotropin-releasing hormone is abbreviated and often referred to as CRH. CRH is chemically classed as a neuropeptide hormone - a protein-like molecule made up of a short chain of amino acids produced in the brain that functions as a hormone. The hypothalamus where CRH is produced is an area of the brain that also controls body temperature, hunger, and thirst. The anterior pituitary where CRH acts is the front portion of the pituitary, a small gland in the head. It secretes hormones that influence growth, sexual development, skin pigmentation, and thyroid function, as well as the function of the adrenal cortex.
Cortisol:  The primary stress hormone. Cortisol is the major natural "glucocorticoid" in humans.
Cortisone:  An adrenocorticoid hormone, a naturally occurring hormone made by and secreted by the adrenal cortex, the outer part (the cortex) of the adrenal gland. In the 1950s, soon after the synthesis of cortisone in the laboratory, it was used in large doses to treat arthritis - before the dangers of such doses became apparent, thus giving hormone therapy a black eye at its inception.
Coryza:  A cold in the head. The word "coryza" came from the Greek "koryza" which is thought to have been compounded from "kara", head + "zeein", to boil. The "boiling over from the head" refers to the runny nose, an all-too-familiar feature of a head cold.
Cosmeceutical:  A cosmetic product claimed to have medicinal or drug-like benefits. Cosmeceutical products are marketed as cosmetics, but reputedly contain biologically active ingredients. Examples include anti-wrinkle skin creams with ingredients such as alpha lipoic acid and dimethylaminoethanol and creams containing "cellular replenishment serum" that supposedly have "antiaging properties."
Cosmid:  DNA from a bacterial virus into which is spliced a small fragment of a genome to be amplified and sequenced. A cosmid is an artificially constructed structure. It is used in cloning (copying) pieces of DNA.
Costal margin:  The lower edge of the chest (thorax) formed by the bottom edge of the rib cage.
Costochondritis:  Costochondritis is inflammation of the cartilage of the chest wall, usually involving that which surrounds the breast bone (sternum). It causes local pain and tenderness of the chest around the sternum.
Cotinine:  The major metabolite (breakdown product) of nicotine. Exposure to nicotine can be measured by analyzing the cotinine level in the blood, saliva, or urine. Since nicotine is highly specific to tobacco smoke, serum cotinine levels track exposure to tobacco smoke and its toxic constituents. Cotinine assays provide an objective quantitative measure that is more reliable than smoking histories or counting the number of cigarettes smoked per day. Cotinine also permits the measurement of exposure to second-hand smoke (passive smoking). Cotinine is an anagram of nicotine. (The 8 letters in the word "nicotine" were rearranged to coin the word "cotinine.")
Cotton rat:  A rodent capable of carrying the types of hantavirus that cause HPS (hantavirus pulmonary syndrome) in the US. The cotton rate is found in the southeastern US and Central and South America. Scientific name: Sigmodon hispidus.
Cough:  A rapid expulsion of air from the lungs typically in order to clear the lung airways of fluids, mucus, or material. Also called tussis.
Cough suppressant:  A drug used to control coughing, particularly with a dry, nagging, unproductive cough.
Coughing syncope:  The temporary loss of consciousness upon coughing. Syncope is the temporary loss of consciousness or, in plain English, fainting.
Coumadin:  a brand name of warfarin, an anticoagulant medication that can be administered orally. It is used for the prophylaxis of thrombosis and embolism in many disorders. Its activity has to be monitored by frequent blood testing for the international normalized ratio (INR). It is also a key ingredient in some rat poisons. Coumadin taken by a woman during pregnancy can cause bleeding into the baby's brain (cerebral hemorrhage), underdevelopment (hypoplasia) of the baby's nose and stippling of the ends (the epiphyses) of the baby's long bones.
Counterpulsation:  A technique that synchronizes an external pump to pump blood with the heart's cycle to assist the circulation and decrease the work load on the heart. Counterpulsation pumps when the heart is between beats (diastole) to increase blood flow and oxygen to the heart. Counterpulsation stops when the heart contracts (systole).
Courier:  In the illegal drug trade, someone who internally conceals and transports an illicit drug. Also called a body packer.
Cousin marriage:  Marriage involving cousins. Everyone carries rare recessive alleles, rare genes that are generally innocuous in the heterozygous state but that in the company of another gene of the same type are capable of causing an autosomal recessive disease. We are all reservoirs for genetic disease. First cousins, as noted, share a set of grandparents. So for any particular allele (gene) in the father, the chance that the mother inherited the same allele from the same source is 1/8. Further, for any gene the father passes to his child, the chance is 1/8 that the mother has the same gene and ½ that she transmits that gene to the child so 1/8 X ½ = 1/16. Thus, a first-cousin marriage has a coefficient of inbreeding of 1/16.
Cow milk allergy:  Casein and whey are the two major proteins of human milk and most milk-based formulas. Some (less than 8% of) infants have a true allergy to the cow proteins that are in milk-based formulas. Infants with true cow milk allergy can develop abdominal pain, diarrhea, rectal bleeding, skin rash, and wheezing when given milk-based formulas. These symptoms will disappear as soon milk-based formula is removed from the diet. (Allergy to cow milk protein is different from lactose intolerance). The treatment of cow milk protein allergy involves using formulas that contain no cow milk, or using formulas that contain "predigested" casein and whey proteins. The predigesting process breaks the whole proteins into smaller pieces or into amino acids. The amino acids and smaller protein pieces are non-allergenic (do not cause allergy). Soy protein formulas contain no cow milk, and are reasonable alternatives for infants with true cow milk allergy. However, some infants have allergy to both cow milk and soy proteins. These infants require a formula in which the cow milk protein (casein) has been "predigested" and specific amino acids added to provide a formula that can provide proper nutrition.
Cowper's gland:  A tiny gland in the male, also known as the bulbourethral gland. A pea-sized gland in the male located behind and to the side of the urethra that discharges a component of seminal fluid into the urethra. There are two bulbourethral glands, one on each side. They are the counterparts of Bartholin's glands in the female. Named after the English anatomist William Cowper (1666-1709).
Cowpox:  A mild skin disease of milk cows, principally confined to the udder and teats, that may be contracted by people from milking an infected cow. People develop vesicles (blebs) which break and form ulcers on the fingers (sometimes called "milker's nodules"). These usually heal without scarring. Cowpox protects against smallpox and was used by Edward Jenner in 1798 for this purpose to confer immunity against smallpox. Cowpox and smallpox belong to the orthopox family of viruses.
Cox-1:  Cyclooxygenase-1, a protein that acts as an enzyme to speed up the production of certain chemical messengers, called prostaglandins, within the stomach. The prostaglandins work within certain cells that are responsible for inflammation and other functions. For example, they promote the production of the natural mucus lining that protects the inner stomach. Cox-1 is normally present in a variety of areas of the body, including not only the stomach but any other site of inflammation.
Cox-1 inhibitor:  An agent that inhibits the action of the enzyme cox-1 (cyclooxygenase-1). The common anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen block the action of both cox-1 and cox-2. Cox-1 inhibitors can reduce inflammation, but they may also decrease the natural protective mucus lining of the stomach. Therefore, these medications can cause stomach upset, intestinal bleeding, and ulcers. In some cases, using a buffered form of a cox-1 inhibitor can eliminate or reduce these adverse effects.
Cox-2:  Cyclooxygenase-2, a protein acts as an enzyme and specifically catalyzes (speeds) the production of certain chemical messengers called prostaglandins. Some of these messengers are responsible for promoting inflammation. When Cox-2 activity is blocked, inflammation is reduced. Unlike cox-1, cox-2 is active only at the site of inflammation, not in the stomach.
Cox-2 inhibitor:  A type of drug that selectively blocks the enzyme cox-2 (cyclooxygenase-2). Blocking this enzyme impedes the production of the chemical messengers called prostaglandins that cause the pain and swelling of arthritis inflammation. Cox-2 inhibitors may not pose as great a risk of injuring the stomach or intestines as cox-1 inhibitors. Cox-2 inhibitors now on the market include celecoxib (brand name: Celebrex) and rofecoxib (brand name: Vioxx).
Coxa valga:  Inward curvature of the hip. Malformation of the hip at birth, such as coxa valga, can increase one's risk for development of osteoarthritis of the hip in later life.
Coxa vara:  Outward curvature of the hip. Malformation of the hip at birth, such as coxa vara, can increase one's risk for development of osteoarthritis of the hip in later life.
Coxsackie virus:  A family of enteroviruses first found in the town Coxsackie south of Albany, New York. The Coxsackie viruses are separable into two groups: A and B. Type A viruses cause herpangina (sores in the throat) and hand, foot and mouth disease. Type B viruses cause epidemic pleurodynia. Both types A and B viruses can cause meningitis, myocarditis and pericarditis, and acute onset juvenile diabetes.
CPAP:  Continuous positive airway pressure. CPAP is an effective treatment for obstructive sleep apnea. CPAP patients during sleep wear a face mask connected to a pump that forces air into the nasal passages at pressures high enough to overcome obstructions in the airway and stimulate normal breathing. The airway pressure delivered into the upper airway is continuous during both inspiration and expiration. Nasal CPAP is currently the best treatment for severe obstructive sleep apnea. CPAP is safe and effective, even in children. Tissues are prevented from collapsing during sleep, and apnea is effectively prevented without surgical intervention. Daytime sleepiness improves or resolves. Heart function and hypertension also improve. And, importantly, the quality of life improves. At first, CPAP patients should be monitored in a sleep lab to determine the appropriate amount of air pressure for them. The first few nights on CPAP tend to be difficult, with patients experiencing less sleep. Many patients at first find the mask uncomfortable, claustrophobic or embarrassing. CPAP is not a cure and must be used every night for life. Non-compliant patients experience a full return of obstructive sleep apnea and related symptoms. Of course, all this ignores the causes of sleep apnea which are toxicity and stress.
CPEO:  Chronic progressive external ophthalmoplegia. Slowly progressive paralysis of certain eye muscles.
CPEO WITH MYPOATHY or Kearns-Sayre syndrome:  A neuromuscular disorder characterized by three primary findings: Progressive paralysis of certain eye muscles (chronic progressive external ophthalmoplegia, or CPEO); Abnormal accumulation of colored (pigmented) material on the retina (atypical retinitis pigmentosa), leading to chronic inflammation and progressive degeneration of the retina; and Heart disease (cardiomyopathy) such as cardiac conduction defects and heart block. Other findings in the syndrome may include muscle weakness, short stature, hearing loss, and the loss of ability to coordinate voluntary movements (ataxia) due to problems in the part of the brain called the cerebellum. Kearns-Sayre syndrome is one of the mitochondrial encephalomyopathies. These disorders are due to defects in the DNA of the mitochondria, the cell structures that produce energy. These defects cause the brain and muscles to function abnormally (encephalomyopathy). In about 80% of cases of Kearns-Sayre syndrome, tests reveal deletions in mitochondrial DNA (mtDNA).
CPEO with ragged-red fibers (Kearns-Sayre syndrome):  A neuromuscular disorder characterized by three primary findings: Progressive paralysis of certain eye muscles (chronic progressive external ophthalmoplegia, or CPEO); Abnormal accumulation of colored (pigmented) material on the retina (atypical retinitis pigmentosa), leading to chronic inflammation and progressive degeneration of the retina; and Heart disease (cardiomyopathy) such as cardiac conduction defects and heart block. Other findings in the syndrome may include muscle weakness, short stature, hearing loss, and the loss of ability to coordinate voluntary movements (ataxia) due to problems in the part of the brain called the cerebellum. Kearns-Sayre syndrome is one of the mitochondrial encephalomyopathies. These disorders are due to defects in the DNA of the mitochondria, the cell structures that produce energy.
CPR:  Acronym for cardiopulmonary resuscitation.
Crabs (Pubic Lice):  Parasitic insects found in the genital area of humans. Pubic lice are usually spread through sexual contact. Rarely, infestation can be spread through contact with an infested person's bed linens, towels, or clothes. A common misbelief is that infestation can be spread by sitting on a toilet seat. This is not likely, since lice cannot live long away from a warm human body. Also, lice do not have feet designed to walk or hold onto smooth surfaces such as toilet seats. Infection in a young child or teenager may indicate sexual activity or sexual abuse.
Crack:  The street name given to cocaine that has been processed from cocaine hydrochloride to a ready-to-use free base for smoking. Rather than requiring the more volatile method of processing cocaine using ether, crack cocaine is processed with ammonia or sodium bicarbonate (baking soda) and water and heated to remove the hydrochloride, thus producing a form of cocaine that can be smoked. The term "crack" refers to the crackling sound heard when the mixture is heated, presumably from the sodium bicarbonate. On the illicit market, crack, or "rock," is sold in small, inexpensive dosage units. Smoking this form of the drug delivers large quantities of cocaine to the lungs, producing effects comparable to intravenous injection. These effects are felt almost immediately after smoking, are very intense, and do not last long. There is great risk associated with cocaine use whether the drug is ingested by snorting, injecting, or smoking. Excessive doses of cocaine may lead to seizures and death from respiratory failure, stroke, cerebral hemorrhage (bleeding into the brain), or heart failure. There is no specific antidote for cocaine overdose. Evidence suggests that users who smoke or inject cocaine may be at even greater risk than those who snort it. Cocaine smokers suffer from acute respiratory problems including coughing, shortness of breath, and severe chest pains with lung trauma and bleeding. In addition, it appears that compulsive cocaine use may develop even more rapidly if the substance is smoked rather than snorted.
Cracked tooth syndrome:  A toothache caused by a broken tooth (tooth fracture) without associated cavity or advanced gum disease. Biting on the area of tooth fracture can cause severe sharp pains. These fractures are usually due to chewing or biting hard objects such as hard candies, pencils, nuts, etc. Sometimes, the fracture can be seen by painting a special dye on the cracked tooth. Treatment usually is to protect the tooth with a crown. However, if placing a crown does not relieve pain symptoms, a root canal procedure may be necessary. Many doctors believe that root canals are invariably infested with bacteria and therefore the better choice is extraction and bridge construction.
Cranial:  1. Pertaining to the cranium or skull. 2. Toward the head. As opposed to caudad (toward the tail). For example, the eye is "cranial" to the jaw.
Cranial arteritis:  A serious disease characterized by inflammation of the walls of the blood vessels (vasculitis). The vessels affected by inflammation are the arteries (hence the name "arteritis"). The age of affected patients is usually over 50 years of age. Cranial arteritis is also known as temporal arteritis and as giant cell arteritis. It can lead to blindness and/or stroke. The disease is detected by a biopsy of an artery. It is treated with high dose cortisone-related medications.
Cranial bone:  Part of the top portion of the skull which protects the brain. The bones of the cranium include the frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.
Cranial dystonia:  A term used to describe dystonia that affects the muscles of the head, face, and neck. Oromandibular dystonia affects the muscles of the jaw, lips, and tongue. The jaw may be pulled either open or shut, and speech and swallowing can be difficult. Spasmodic dysphonia involves the muscles of the throat that control speech. Also called spastic dysphonia or laryngeal dystonia, it causes strained and difficult speaking or breathy and effortful speech. Meige's syndrome is the combination of blepharospasm and oromandibular dystonia and sometimes spasmodic dysphonia. Spasmodic torticollis can be classified as a type of cranial dystonia.
Cranial nerve I:  The first nerve to emerge from or enter the skull (the cranium). The first cranial nerve is the olfactory nerve which permits the sense of smell. The cranial nerves emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves.
Cranial nerve II:  The second cranial is the optic nerve, the nerve that connects the eye to the brain and carries the impulses formed by the retina - the nerve layer that lines the back of the eye, senses light and creates the impulses - to the brain which interprets them as images.
Cranial nerve III:  The third cranial nerve is the oculomotor nerve which branches to four of the six tiny muscles which control the movement of the orbit (eyeball).
Cranial nerve IV:  The fourth cranial nerve, the trochlear nerve, is the nerve supply to the superior oblique muscle of the eye, one of the muscles that moves the eye. Paralysis of the trochlear nerve results in rotation of the eyeball upward and outward (and, therefore, double vision).
Cranial nerve IX:  The ninth cranial nerve is the glossopharyngeal nerve. The glossopharyngeal nerve supplies the tongue, throat, and one of the salivary glands (the parotid gland). Problems with the glossopharyngeal nerve result in trouble with taste and swallowing.
Cranial nerve V:  The fifth cranial nerve is the trigeminal nerve. The trigeminal nerve is quite complex. It functions both as the chief nerve of sensation for the face and the motor nerve controlling the muscles of mastication (chewing). Problems with the sensory part of the trigeminal nerve result in pain or loss of sensation in the face. Problems with the motor root of the trigeminal nerve result in deviation of the jaw toward the affected side and trouble chewing. The term "trigeminal" comes from the Latin trigeminus meaning "threefold," referring to the three divisions (ophthalmic, maxillary and mandibular) of this nerve.
Cranial nerve VI:  The sixth cranial nerve is the abducent nerve. It is a small motor nerve that has one task: to supply a muscle called the lateral rectus muscle of the eye that moves the eye outward. Paralysis of the abducent nerve causes inward turning of the eye (internal strabismus) leading to double vision. The word "abducent" comes from the Latin "ab-", away from + "ducere", to draw = to draw away. The abducent (or abducens) operates the lateral rectus muscle that draws the eye toward the side of the head. The abducent nerve is also called the abducens nerve.
Cranial nerve VII:  The facial nerve is the seventh cranial nerve. The facial nerve supplies the muscles of facial expression. Paralysis of the facial nerve causes a characteristic picture with drooping of one side of the face, inability to wrinkle the forehead, inability to whistle, inability to close the eye and deviation of the mouth toward the other side of the face. Paralysis of the facial nerve is called Bell's palsy.
Cranial nerve VIII:  The eighth cranial nerve is the vestibulocochlear nerve. The vestibulocochlear nerve is responsible for the sense of hearing and it is also pertinent to balance, to the body position sense. Problems with the vestibulocochlear nerve may result in deafness, tinnitus (ringing or noise in the ears), dizziness, vertigo and vomiting.
Cranial nerve X:  The tenth cranial nerve, and one of the most important, is the vagus nerve. The vagus nerve originates in the medulla oblongata, a part of the brain stem. The vagus nerve is a remarkable nerve that relates to the function of numerous structures in the body. The vagus nerve supplies nerve fibers to the pharynx (throat), larynx (voice box), trachea (windpipe), lungs, heart, esophagus and most of the intestinal tract (as far as the transverse portion of the colon). And the vagus nerve brings sensory information back from the ear, tongue, pharynx and larynx. The term "vagus" (Latin for "wandering") is apt because the vagus nerve wanders all the way down from the brainstem to the colon, a long wandering trek. Complete interruption of the vagus nerve causes a characteristic syndrome. The back part of the palate (the soft palate) droops on that side. The capacity to gag (the gag reflex) is also lost on that side. The voice is hoarse and nasal. The vocal cord on the affected side is immobile. The result is dysphagia and dysphonia (trouble swallowing and trouble speaking). One of the best known branches of the vagus nerve is the recurrent laryngeal nerve. After leaving the vagus nerve, the recurrent laryngeal nerve goes down into the chest and then loops back up to supply the larynx (the voice box). Damage to the recurrent laryngeal nerve can result from diseases inside the chest (intrathoracic diseases) such as a tumor or an aneurysm (ballooning) of the arch of the aorta or of the left atrium of the heart. The consequence is laryngeal palsy, paralysis of the larynx (the voice box), on the affected side. Laryngeal palsy can also be caused by damage to the vagus nerve before it gives off the recurrent laryngeal nerve.
Cranial nerve XI:  The eleventh cranial nerve is the accessory nerve. The accessory is so-called because, although it arises in the brain, it receives an additional (accessory) root from the upper part of the spinal cord. The accessory nerve supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. Damage to the accessory nerve can be isolated (confined to the accessory nerve) or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy (nerve disease) can sometimes occur and recur for unknown reasons. Most patients recover. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.
Cranial nerve XII:  The twelfth cranial nerve is the hypoglossal nerve. The hypoglossal nerve supplies the muscles of the tongue.
Cranial nerves:  Nerves that emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge or enter the vertebral column. Cranial nerves come directly from the brain through the skull. The cranial nerves are nerves of the brain. There are 12 cranial nerves each of which is accorded a Roman numeral and a name:

Cranial nerve I: The olfactory nerve,
Cranial nerve II: the optic nerve,
Cranial nerve III: the oculomotor nerve,
Cranial nerve IV: the trochlear nerve,
Cranial nerve V: the trigeminal nerve,
Cranial nerve VI: the abducent nerve,
Cranial nerve VII: the facial nerve,
Cranial nerve VIII: the vestibulocochlear nerve,
Cranial nerve IX: the glossopharyngeal nerve,
Cranial nerve X:the vagus nerve,
Cranial nerve XI: the accessory nerve, and
Cranial nerve XII: the hypoglossal nerve.

Craniocleidodysostosis:  A genetic (inherited) disorder of bone development characterized by: Typical cranial and facial abnormalities with square skull, late closure of the sutures of the skull, late closure of the fontanels (the soft spots), low nasal bridge, delayed eruption of the teeth, abnormal permanent teeth, etc. absent or incompletely formed collar bones (the "cleido-" part refers to the clavicles, the collar bones) The child with this disorder can bring its shoulders together or nearly so. The disorder is transmitted in an autosomal dominant manner. A parent with the condition has a 50:50 chance that each of their children will have the condition. Boys and girls stand an equal chance of being affected. The gene for the condition has been found on chromosome 6 (specifically, in band p21).
Craniology:  The study of variations in size, shape, and proportion of the skull (cranium). Also known as phrenology, it was a pseudoscience of the 18th and 19th centuries based on the belief that a person's character could be learned by looking with care at the shape of their head and noting each and every bump and depression in their skull. The individual mental faculties were believed to be contained in neat compartments in the cerebral cortex and the size of these faculties were supposed to be reflected by the configuration of the skull. The best known model of phrenology was that of Gall who marked off the places of twenty-six organs on the head.
Craniometaphyseal dysplasia:  An inherited skeletal condition that involves abnormal bone formation and abnormal mineralization of the skull as well as the long bones. There is increased density of craniofacial bones beginning at the base of the skull during early childhood.
Craniopagus:  Conjoined twins whose heads are fused together. From cranio-, relating to the cranium + the Greek pagos, referring to something fixed. Synonyms are: syncephaly and janiceps. (from Janus, the Roman God of gates with faces in both directions).
Craniopagus parasiticus:  Conjoined twins joined at the head (craniopagus) in which a rudimentary head (with little or no body) is attached to the head of the larger and usually more normal twin.
Craniopharyngioma:  A type of benign brain tumor that develops from embryonic tissue that forms part of the pituitary gland. Pressure on the pituitary by the tumor reduces the availability of the hormone vasopressin, raising the pressure within the cranium. A craniopharyngioma usually includes hard, calcified components within the tumor itself, and disrupts normal skull development in its vicinity. Treatment is usually surgical.
Craniosynostosis:  Premature fusion of the cranial sutures (the fibrous joints between the bones of the skull) in an infant, preventing normal growth of the baby's head. Craniosynostosis involving some but not all of the sutures causes an abnormally shaped skull. Premature closure of all of the sutures results in microcephaly (an abnormally small head) which arrests the normal growth and development of the baby's brain and may result in developmental delay and mental retardation. Early detection of the condition is therefore of great importance. Treatment is surgery designed to keep the sutures open.
Craniotomy:  A surgical operation in which an opening is made in the skull.
Cranium:  The upper portion of the skull, which protects the brain. The bones of the cranium include the frontal, parietal, occipital, temporal, sphenoid, ethmoid, lacrimal, and nasal bones; the concha nasalis; and the vomer.
Crapulence:  Sickness or indisposition resulting from an excess of drinking (or eating). Crapulence is an almost exact synonym for a hangover.
Crapulent:  Ill from excessive drinking or eating. Surcharged with liquor, or sick with intemperance.
Cream:  A word with many meanings that, in medicine and pharmacy, refers to a water-soluble preparation applied to the skin. An ointment differs from a cream in that it has an oil base.
Creatine:  A compound the body synthesizes (makes) to store energy for later use. The storage of energy occurs when phosphate molecules are attached to creatine to create creatine phosphate. Creatine phosphate is capable of donating phosphate to ADP (adenosine diphosphate in order to make ATP (adenosine triphosphate). ATP can then be converted into ADP with release of energy. Creatine is sold as a dietary supplement and is used by athletes as a "legal steroid" to increase muscle bulk. It must not be confused with creatinine, a protein breakdown product used to measure kidndy function.
Creatinine:  A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body's creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and dispose of it in the urine. Although it is a waste, creatinine serves a vital diagnostic function. Creatinine has been found to be a fairly reliable indicator of kidney function. As the kidneys become impaired the creatinine will rise. Abnormally high levels of creatinine thus warn of possible malfunction or failure of the kidneys, sometimes even before a patient reports any symptoms. It is for this reason that standard blood and urine tests routinely check the amount of creatinine in the blood. Normal levels of creatinine in the blood are approximately 0.6 to 1.2 milligrams (mg) per deciliter (dl) in adult males and 0.5 to 1.1 milligrams per deciliter in adult females.
Creatinine clearance test:  A test that helps determine whether the kidneys are functioning normally. Specifically, the creatinine-clearance test gauges the rate at which a waste, creatinine, is "cleared" from the blood by the kidneys. Creatinine is produced from the metabolism of protein as when muscles burn energy. Most creatinine is then filtered out of the blood by the kidneys and excreted in urine. The rate of creatinine clearance is measured by first noting the volume of urine excreted in a given time period, such as 24 hours. Then the amount of creatinine in the excreted urine is measured and compared with the amount of creatinine circulating in the blood. If the kidneys are not removing enough creatinine, the level of creatinine in the urine will fall. And consequently the level of creatinine in the blood will rise. When the kidneys fail to clear enough creatinine and other wastes from the blood, the wastes build up in the bloodstream. Symptoms of kidney disease -- including swelling (edema), nausea, and high blood pressure -- may develop. However, the creatinine-clearance test can usually detect waste buildup in the blood before it threatens the body. Doctors can then have an opportunity to eliminate the cause of the buildup and restore blood creatinine to normal levels. A creatinine-clearance test, thus, plays a key role in preventive medicine as well as in diagnostic and therapeutic medicine.
Crepitus:  A clinical sign in medicine characterized by a peculiar crackling, crinkly, or grating feeling or sound under the skin, around the lungs, or in the joints. Crepitus in soft tissues is often due to gas, most often air, that has penetrated and infiltrated an area where it should not normally be, as for example the soft tissues beneath the skin (a condition called subcutaneous emphysema). Crepitus in a joint can represent cartilage wear in the joint space. The term "crepitus" is taken directly from the Latin "crepitus" meaning "a crackling sound or rattle."
CREST syndrome:  A limited form of scleroderma, a disease of connective tissue with the formation of scar tissue (fibrosis) in the skin and sometimes also in other organs of the body. CREST stands for: C ... Calcinosis (the formation of tiny deposits of calcium in the skin), R ... Raynaud's phenomenon (spasm of the tiny artery vessels supplying blood to the fingers, toes, nose, tongue, or ears), E ... Esophagus (esophageal involvement by the scleroderma), S ... Sclerodactyly (localized thickening and tightness of the skin of the fingers or toes) and T ... Telangiectasias (dilated capillaries that form tiny red areas, frequently on the face, hands and in the mouth behind the lips).
Cretinism:  Congenital hypothyroidism (underactivity of the thyroid gland at birth) resulting in growth retardation, developmental delay and other abnormal features. Can be due to deficiency of iodine in the mother's diet during pregnancy. The condition is detected today by newborn thyroid screening.
Creutzfeldt-Jakob disease (CJD):  A degenerative, invariably fatal brain disorder. It affects about one person in every one million people per year worldwide; in the United States there are about 200 cases per year. CJD usually appears in later life and runs a rapid course. Typically, onset of symptoms occurs about age 60, and about 90% of patients die within a year. In the early stages of disease, patients may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and involuntary movements, blindness, weakness of extremities, and coma may occur. There are three major categories of CJD: Sporadic CJD: In sporadic CJD, the disease appears even though the person has no known risk factors for the disease. This is by far the most common type of CJD and accounts for at least 85% of cases. Hereditary CJD: In hereditary CJD, the person has a family history of the disease and/or tests positive for a genetic mutation associated with CJD. About 5 to 10% of cases of CJD in the United States are hereditary. Acquired CJD: In acquired CJD, the disease is transmitted by exposure to brain or nervous system tissue, usually through certain medical procedures. There is no evidence that CJD is contagious through casual contact with a CJD patient. Since CJD was first described in 1920, fewer than 1% of cases have been acquired CJD. CJD belongs to a family of human and animal diseases known as the transmissible spongiform encephalopathies (TSEs). Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges under a microscope. CJD is the most common of the known human TSEs. Other human TSEs include kuru, fatal familial insomnia (FFI), and Gerstmann-Straussler-Scheinker disease (GSS).
Crib death:  The sudden and unexpected death of a baby with no known illness, typically affecting infants from 2 weeks to 6 months of age while sleeping. Crib death is now called Sudden Infant Death Syndrome (SIDS). Babies at an increased risk for SIDS include those with a brother or sister who died of SIDS; children whose mothers smoked or used heroin, methadone, or cocaine during pregnancy; infants born weighing less than 4.4 pounds (2000 grams); children with an abnormal breathing pattern with long periods without taking a breath (apnea); and babies who sleep on their stomachs. Since babies who sleep on their stomachs are at least 3 times more likely to die of SIDS than babies who sleep on their backs, children's health authorities such as the American Academy of Pediatrics recommend always placing infants on their backs to sleep. Many ideas have been proposed to explain SIDS, but none has been comprehensive or convincing until the theory presented by Barry Richardson, a British expert in materials degradation. His theory was validated by the research of Dr. T. James Sprott, a New Zealand chemist and forensic scientist. Their research demonstrates that SIDS is the result of accidental poisoning due to toxic gases released from baby mattresses. These gases are produced by the interaction of common household fungi with phosphorus, arsenic and antimony, chemicals which are either present naturally in the mattresses or which have been added as flame retardant chemicals. The fungi are harmless by themselves but feed on these chemicals. The byproducts are the gases phosphine (PH3), arsine (AsH3) and stibine (SbH3). These nearly odorless gases breathed even in small quantities for an extended time can interrupt the choline/acetylcholine transfer of nervous impulses from the brain to the heart and lungs. This shuts down the central nervous system; heart function and breathing stop. The gases are heavier than air, and about 1,000 times more poisonous than carbon monoxide. A baby sleeping on its stomach is in the zone above the mattress where the gases are most dense. Repeated exposure to these gases, especially in combination with other insults to a baby’s immune system can result in toxic overload and death. There has been no research to date which has disproved this theory or offered a better one.
Crick:  1. A painful sudden spasmodic stiffness in the muscles of the neck or back.
Crick, Francis:  British biologist (1916-2004) who shared the 1962 Nobel prize in Medicine and Physiology with James Watson and Maurice Wilkins for "discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material." The discovery of the structure of DNA as a double helix by Watson and Crick (with assists by Wilkins and, especially, by the uncredited Rosalind Franklin) was at the heart of this award.
Crime scene investigation (CSI):  The use of physical evidence at the scene of the crime and the use of deductive and inductive reasoning to gain knowledge of the events surrounding the crime. Crime scene investigation is multidisciplinary and involves a systematic search of the crime scene; meticulous observation and documentation of the scene; photography and sketching of the scene; the identification, processing and collection of physical evidence such as fingerprints, footwear impressions, hair, fibers, biological fluids, and materials for DNA analysis; and. perhaps most important, the application of careful reasoning to the facts.
Crimean-Congo hemorrhagic fever:  A viral disease characterized by hemorrhage (bleeding) and fever; a severe disease with a high mortality (death) rate. The geographical distribution of the virus, like that of the tick that carries it, is widespread. CCHF has been found in Africa, Asia, the Middle East and Eastern Europe.
Critical care (Intensive care):  The specialized care of patients whose conditions are life-threatening and who require comprehensive care and constant monitoring, usually in intensive care units.
Critical incident stress management:  A way of providing crisis counseling that includes debriefing people who have exposed to a traumatic event. Although this method has been widely practiced, there is no convincing evidence it is effective or beneficial.
Crocodile tears syndrome:  Spontaneous tearing in parallel with the normal salivation of eating. The crocodile tears syndrome occurs most often following facial paralysis when nerve fibers destined for a salivary gland are damaged and by mistake regrow into a tear gland. Also called Bogorad's syndrome, gustatolacrimal reflex, paroxysmal lacrimation.
Crohn's colitis:  Crohn's disease involving only the large intestine. Crohn disease is a chronic inflammatory disorder, primarily involving the small and large intestine, but which can affect other parts of the digestive system as well. It is named for the doctor who first described the disease in 1932. The disease is usually diagnosed in persons in their teens or twenties, but can occur at any point in life. Crohn disease can be a chronic, recurrent condition or can cause minimal symptoms with or even without medical treatment. In mild forms, Crohn disease causes small scattered shallow crater-like areas (erosions) called aphthous ulcers in the inner surface of the bowel. In more serious cases, deeper and larger ulcers can develop, causing scarring and stiffness and possibly narrowing of the bowel, sometimes leading to obstruction. Deep ulcers can puncture holes in the bowel wall, leading to infection in the abdominal cavity (peritonitis) and in adjacent organs.
Crohn's disease:  A chronic inflammatory disease, primarily involving the small and large intestine, but which can affect other parts of the digestive system as well. It is named for Burrill Crohn, the American gastroenterologist who first described the disease in 1932. Crohn disease is usually diagnosed in persons in their teens or twenties, but can come to the fore at any point in life. It can be a chronic, recurrent condition or can cause minimal symptoms with or even without medical treatment. In mild forms, Crohn disease causes small scattered shallow crater- like areas (erosions) called aphthous ulcers in the inner surface of the bowel. In more serious cases, deeper and larger ulcers can develop, causing scarring and stiffness and possibly narrowing of the bowel, sometimes leading to obstruction. Deep ulcers can puncture holes in the bowel wall, leading to infection in the abdominal cavity (peritonitis) and in adjacent organs. Abdominal pain, diarrhea, vomiting, fever, and weight loss are common symptoms. Crohn disease can be associated with reddish tender skin nodules, and inflammation of the joints, spine, eyes, and liver. Diagnosis is commonly made by x-ray or colonoscopy. Treatment includes medications that are anti-inflammatories, immune suppressors or antibiotics. Surgery can be necessary in severe cases. Genetic factors contribute to the causation of Crohn disease. One of the genes has been shown to be on chromosome 14 in region 14q11-12.
Crohn's enteris:  Crohn's disease (regional enteritis) involving only the small intestine.
Crohn's enterocolitis:  Crohn's disease (involves small and large intestines).
Crohn's ileitis:  Inflammation of the ileum (the farthest segment of the small intestine) due to Crohn's disease.
Crohn's ileocolitis:  Crohn's disease involving the ileum (the lowest portion of the small intestine) and the colon (the large intestine)
Cross training:  Doing two or more aerobic activities such as jogging, bicycling, and swimming on a regular basis.
Cross-section:  In anatomy, a cross-section is a transverse cut through a structure or tissue. The opposite of a cross-section is a longitudinal section. By analogy, a study may be cross-sectional or longitudinal.
Cross-sectional study:  A study done at one time, not over the course of time. A cross-sectional study might be of a disease such as AIDS at one point in time to learn its prevalence and distribution within the population. Also known as a synchronic study.
Cross-species transplantation (Xenotransplantation):  Transplantation from one species to a foreign one. The rationale for xenotransplantation has included the short supply of human organs for transplantation. The first surgeon to do an animal-to-human heart transplant was Dr. James D. Hardy. After doing the first human lung transplant in 1963, Hardy did the first animal-to-human heart transplant in 1964 at the University of Mississippi. The transplant involving a chimpanzee heart was done three years before the first human-heart transplant (by Christiaan Barnard). Perhaps the most famous case of cross-species transplantation was that of a heart from a baboon to Baby Fae in 1984, performed by Dr. Leonard Bailey at Loma Linda University, California. Baby Fae lived for 20 days after the operation. The first to show that nonhuman organs could be transplanted to humans and function for a significant period of time was Dr. Keith Reemtsma (1925-2000).
Crossed embolism:  Passage of a clot (thrombus) from a vein to an artery. When clots in veins break off (embolize), they travel first to the right side of the heart and then, normally, then to the lungs where they lodge. The lungs act as a filter to prevent the clots from entering the arterial circulation. However, when there is a hole in the wall between the two upper chambers of the heart (an atrial septal defect), or the lower chambers (a ventricular septal defect) a clot can cross paradoxically from the right to the left side of the heart, then pass into the arteries. Once in the arterial circulation, a clot can travel to the brain, block a vessel there, and cause a stroke (cerebrovascular accident). Because of the risk of stroke from crossed embolism, it is usually recommended that even small atrial septal defects be closed (repaired). Also called: paradoxical embolism.
Crossing over:  The exchange of genetic material between two paired chromosomes. Crossing over is a way to recombine the genetic material so that each person (except for identical twins) is genetically unique.
Crossover study:  A type of clinical trial in which the study subjects receive each treatment in a random order. With this type of study, every patient serves as his or her own control.
Croup:  A respiratory problem that occurs mainly in children, particularly from 2 to 4 years of age, due to an infection of the respiratory tree -- the larynx (voice box), the trachea (windpipe), and the bronchial tubes. The symptoms of croup include a cough that sounds like a barking seal and a harsh crowing sound when the child is inhaling. A low-grade fever (around 100° to 101°) is common. The child may become very frightened. The major concern in croup is breathing difficulty as the air passages narrow. Croup is most often caused by a virus, less often by a bacteria. Treatment includes moist air, saline (salt water) nose drops, decongestants, cough suppressants, pain medication, fluids, and occasionally antibiotics. Close monitoring of the breathing of a child with croup is valuable, especially at night when croup usually gets worse. Croup may last up to a week. Each night tends to be better than the last. While most children recover from croup without hospitalization, some children can develop trouble breathing that is life-threatening. Therefore, staying in close contact with the doctor during this illness is important.
Crown:  1. Also in dentistry, a type of restoration that covers all or most of the natural tooth. 3. In anatomy, the top of the head, as in the crown-rump length of a fetus. 4. In obstetrics, when a generous portion of the fetal scalp (the crown) become visible at the vaginal opening during labor. Soon after the baby crowns, delivery usually occurs. 2. In dentistry, the portion of the tooth that is covered by enamel.
CRP: C-reactive protein:  a lab test which when positive reflects inflammation and tissue breakdown. A sub-test called High Sensitivity C-reactive protein or Cardiac C-reactive protein is a marker for inflammation (and probable plaque formation) in the vascular system.
Cruciate:  Cross-shaped. "Cruciate" comes from the Latin "crux" which means "cross". (That is the crux of this matter).
Cruciate ligaments:  The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide stability and strength to the knee joint. The anterior cruciate ligament is in the front. The posterior cruciate ligament crosses behind the anterior cruciate ligament within the joint.
Cry for help:  An expression of suicidal intent in the hope of receiving help and being rescued. A cry for help may take many different forms such as a telephone call, a message left on an answering phone, a note left in a conspicuous place, or an e-mail message. It may also be a symbolic gesture such as a superficial cut on the wrist.
Cryo-electron microscopy:  An electron microscopic technique that involves freezing the biological sample in order to view the sample with the least possible distortion and the fewest possible artifacts. Abbreviated as cryo-EM. The advantages of cryo-EM over traditional EM techniques include the preservation of the sample in a near-native hydrated state without the distortions from stains or fixatives needed for traditional EM. With image processing and averaging of multiple images, cyro-EM provides high resolution information (below 10 anstroms).
Cryoglobulin:  An abnormal blood protein that has the unusual properties of precipitating from the blood serum when it is chilled and redissolving when it is rewarmed. Cryoglobulins are gamma globulins with a molecular weight of approximately 200,000. Cryoglobulins can cause problems by causing the blood to be abnormally "thick" which increases the risk of blood clots forming in the brain (stroke), eyes, and heart. Cryoglobulins are also associated with inflammation of blood vessels (vasculitis) which increases the risk of blockage of arteries. Cryoglobulins are a key part of a condition called essential mixed cryoglobulinemia. Cryoglobulins can also accompany diseases such as multiple myeloma, dermatomyositis, and lymphoma. Sometimes small amounts of cryoglobulin are discovered by accident in the lab in a serum sample from someone with no apparent symptoms. The condition is called cryoglobulinemia. There is a condition called essential mixed cryoglobulinemia (EMC) involves cryoglobulin proteins which are a mixture of various antibody types that form for unknown ("essential" - a medical word for "we don't know why") reasons. EMC is characterized by joint pains and swelling (arthritis), enlargement of the spleen, skin vasculitis with purplish patches, and nerve, kidney and heart disease. Treatment is with medications which reduce inflammation and suppress the immune system. Plasmapheresis, in which the blood's serum is replaced with saline (salt water solution), may be done in severe cases. Essential mixed cryoglobulinemia is treated with combinations of medications which reduce inflammation and suppress the immune system. Medications used include nonsteroid antiinflammatory drugs (ibuprofen, aspirin, and others), cortisone preparations (Prednisone, Prednisolone), cyclophosphamide (Cytoxan), chlorambucil (Leukeran), and azathioprine (Imuran). Recent studies have demonstrated some benefit of using interferon-alpha for those patients with evidence of hepatitis C virus, particularly those with mild disease or in those with remission of manifestations after immune suppression treatment.
Cryophobia:  An abnormal and persistent fear of cold, including cold weather and cold objects. Sufferers from cryophobia experience anxiety even though they realize their fear is irrational. To avoid cold, they may live in a warm climate, dress more warmly than necessary, stay indoors on cold days, and avoid cold foods and ice cubes. "Cryophobia" is derived from the Greek kryos (cold, frigid) and phobos (fear). "Kryos" has given us English words such as "cryometer" (a thermometer for measuring very cold temperatures) and "cryotherapy" and "cryosurgery" (medical techniques that freeze and destroy diseased tissue). Related term: Thermophobia, fear of heat.
Cryopreservation:  The process of cooling and storing cells, tissues, or organs at very low temperatures to maintain viability. For example, the technology of cooling and storing cells at a temperature below the freezing point (-196 C) permits high rates of survivability upon thawing. In Greek "kryos" = cold. Cryopreservation is cold storage for the purpose of preservation.
Cryoprobe:  A surgical probe, a long slender pointed surgical instrument, used to apply extreme cold to tissues. From cryo- from the Greek kryos meaning cold + probe.
Cryoprotectant:  A chemical component of a freezing solution used in cryopreservation (the process of cooling and storing cells, tissues, or organs at very low temperatures to maintain viability). The purpose of the cryoprotectant is to help protect what is being frozen from freeze damage. The chemical glycerol, for example, is commonly used as a cryoprotectant to protect frozen red blood cells.
Cryostat:  A chamber that can maintain very low temperatures. Medical laboratories use a cryostat to preserve frozen tissue samples while a microtome, an extremely sharp cutting instrument mounted inside cryostats, slices the tissue into pieces thin enough to be observed under a microscope. The sliced piece must be so thin as to look nearly transparent. A pathologist, a laboratory doctor trained to identify evidence of disease in microscopic structures, then examines the slice to confirm or rule out the presence of a disease, such as cancer. Use of frozen tissue samples enables physicians to examine tissue and diagnose its condition more quickly than if the tissue had been preserved without freezing and is used to make diagnoses during surgical procedure in order to guide the next stage of surgery. For example, if a tumor is found to be benign or malignant, spread or not spread, can determine whether it is surgically removed or not.
Cryosurgery:  Treatment performed with an instrument that freezes and destroys abnormal tissue.
Cryotherapy:  The local or general use of low temperatures in medical therapy. Also called crymotherapy. Cryotherapy is considered an extremely effective treatment for muscular, tendon and ligament injuries.
Crypt:  In anatomy, a crypt is variously a blind alley, a tube with no exit, a depression, or a pit -- in an otherwise fairly flat surface. Cryptic in the case of the tonsils refer to the tonsillar crypts which are little pitlike depressions in the tonsils. The words crypt and cryptic come from the Greek kryptos meaning hidden or concealed. Thus, cryptic tonsillitis may be hidden, concealed because it is down in the pits (of the tonsil).
Cryptic:  Hidden. Cryptic tonsillitis is hidden within the depths of the tonsil.
Cryptitis:  A term that is used to describe one of the abnormalities that is seen under the microscope when small intestinal or colonic tissue is examined. The intestinal crypts are tubular structures composed of cells that protrude from the inner lining of the intestines and into the walls of the intestines. These crypts contain the cells that give rise to all the other cells that move out of the crypts and eventually line the inner lining of the intestines. Inflammation of the crypts is known as cryptitis. Cryptitis is seen in inflammatory bowel disease, both Crohn's and Ulcerative Colitis, but it also can be seen in other inflammatory conditions of the intestines. It is not a disease itself but a histologic manifestation of several different diseases. Cryptitis also may refer to inflammation in the anus. Two centimeters from the anal orifice (anus) the lining tissue of the anus begins to change into the specialized lining of the colon. This junction is called the pectinate line. At the pectinate line are small mounds of tissue that protrude into the anal canal. Between these protrusions into the anus are small out-pouchings from the anus and into the surrounding tissues. These out-pouchings are the anal crypts. Although they are covered with flaps of anal lining tissue, the anal crypts communicate with the anus and colon above. Inflammation of the crypts, probably caused by the trauma of passing stool and/or infection, is referred to as cryptitis. If infection progresses, it can extend further into the surrounding tissues and lead to the formation of an abscess or fistula.
Crypto:  Popular name for both the parasite, Cryptosporidium parvum, and the disease it causes, cryptosporidiosis (see below)
Cryptography:  The encoding and decoding of secret messages. Cryptography in genetics: The term "cryptography" can be applied to human DNA since the message of life is encoded in DNA. And for eons even the existence of DNA was unknown and the information therein an unfathomed mystery. The decoding of DNA in the human genome project is essentially an exercise in cryptography, the greatest piece of cryptography ever undertaken in human history. However, this cryptographic project is incomplete since, although the sequence of most of the DNA has been determined, we are still far from understanding all of the many messages encoded within it.
Cryptorchidism:  Failure of descent of one or both of the testes into the scrotum. The testes first develop within the abdomen before birth and then normally descend into the scrotum. Cryptorchidism is also called undescended testes. Males with cryptorchidism that is not surgically corrected in early childhood are at increased risk for developing testicular cancer.
Cryptosporidiosis:  An intestinal infection characterized by diarrhea caused by a microscopic parasite, Cryptosporidium parvum. The parasite lives in the small intestine of humans and animals who pass it in their feces. The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it resistant to chlorine disinfection. Both the disease and the parasite are popularly known as "Crypto." The disease is also called cryptosporidium enteritis. Crypto is one of the most common causes of waterborne disease in the world, including the US. It is transmitted by the fecal-oral route. Outbreaks have been traced to different sources such as contaminated water supplies, swimming pools and lakes, and unpasteurized cider. Crypto can infect people of all ages. The disease is usually self-limited and resolves in about 2 weeks although young children and pregnant women are among those who are especially susceptible to dehydration. However, the main danger that Crypto presents is for people with immunodeficiency who are at risk for wasting and malnutrition which can be so severe as to be life-threatening. The diagnosis of Crypto may be confirmed by testing stool samples for ova and parasites. There is no reliable treatment for the disease. Dehydration should be prevented or treated. The immune system of people with immunodeficiency should, if possible, be strengthened. For persons with AIDS, antiretroviral therapy that improves the immune status also decreases or eliminates the symptoms of Crypto. To prevent Crypto, proper sanitation and hygiene are essential. People who are immunodeficient it is recommended that they boil water for at least 1 minute. Certain water filters can reduce the risk by filtering out Crypto.
CSF:  1. Cerebrospinal fluid. 2. Colony-stimulating factor.
CSF (cerebrospinal fluid):  A watery fluid, continuously produced and absorbed, which flows in the ventricles (cavities) within the brain and around the surface of the brain and spinal cord. The CSF is produced by the choroid plexus, a series of infolded blood vessels projecting into the cerebral ventricles, and it is absorbed into the venous system. If production exceeds absorption, the CSF pressure rises and the result is hydrocephalus (literally water on the brain) which involves expansion of the ventricles (under pressure) and destruction of brain tissue. This can also occur if the CSF pathways are obstructed and CSF accumulates.
CSF (colony-stimulating factor):  A laboratory-made agent similar to a substance in the body that stimulates the production of blood cells. The colony-stimulating factors (CSFs) include granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Treatment with colony-stimulating factors can help the blood-forming tissue recover from the effects of chemotherapy and radiation therapy.
CT:  Abbreviation for: 1. Cognitive therapy; and, more often today 2. Computerized tomography, as in CT scan.
CT cell:  Cytotoxic T-lymphocyte (see below).
CT colography:  A method for examining the colon by taking a series of x-rays and then using a computer to reconstruct three-dimensional pictures (a CT scan) of the interior surfaces of the colon from these x-rays. The pictures can be saved, manipulated to better viewing angles, and reviewed after the procedure. The procedure requires a 48-hour low-fiber diet and a complete bowel cleansing. If something suspicious is noted, a regular colonoscopy is needed to biopsy or remove it. It results in about 15% false positives (misleading readings that unnecessarily require a regular colonoscopy). It is also not yet known whether it can reliably detect flat adenomas which, like polyps, can give rise to colon cancer. Also called Virtual Colonoscopy.
CT scan (computerized tomography scan):  Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them into pictures on a screen. The CT scan can reveal some soft-tissue and other structures that cannot even be seen in conventional X-rays. Using the same dosage of radiation as that of an ordinary X-ray machine, an entire slice of the body can be made visible with about 100 times more clarity with the CT scan. The tomograms ("cuts") for CT are usually made 5 or 10 mm apart. The CT machine rotates 180 degrees around the patient's body. The machine sends out a thin X-ray beam at 160 different points. Crystals positioned at the opposite points of the beam pick up and record the absorption rates of the varying thicknesses of tissue and bone. The data are then relayed to a computer that turns the information into a 2-dimensional cross-sectional image. The CT scanner was invented in 1972 by the British engineer Sir Godfrey N. Hounsfield and the South African (later American) physicist Alan Cormack. CT scanning was already in general use by 1979, the year Hounsfield and Cormack were awarded the Nobel Prize in Medicine or Physiology for its development. The CT scan is also known as the CAT (computerized axial tomography) scan.
CT, electron beam:  Also known as Ultrafast CT (computerized tomography), this is a new (and controversial) noninvasive test for the detection of coronary artery disease (CAD). It is designed to measure calcium deposits in the coronary arteries. In patients with CAD, the plaques which make up the blockages contain significant amounts of calcium, which can be detected with Ultrafast CT. This test will identify calcium in blockages as mild as 10-20%, which would not be detected by standard physiologic stress testing. The importance of detecting such mild blockages is controversial, however, because the only "treatment" that is used for such blockages typically involves risk factor modification. A potential limitation of Ultrafast CT is that only a total calcium score is reported. This means that two or three separate blockages of about 30% each will result in the same score as a single 70-80% blockage. The Ultrafast CT does not give an image of specific separate areas of calcification. The major value of Ultrafast CT appears to be in screening young patients with one or more risk factors for the development of CAD. Ultrafast CT scanning is of limited value for older patients in whom some degree of calcification is commonly found. Additionally, for the reasons described above, the detection of some calcification may not be reflective of significant CAD. Ultrafast CT was reported to be a better test than treadmill-ECG or technetium-stress test for detecting CAD (J Am Coll Cardiol 2000;36:32-38,326-340). The authors favored it as "a reasonable alternative to traditional stress testing" (pointing also to its cost, brief test time and the fact that a physician does not usually need to be present during the scan). In the same journal, the American College of Cardiology and the American Heart Association issued a consensus statement opposing the widespread use of Ultrafast CT. The controversy continues.
CTL:  Cytotoxic T-lymphocyte (see below).
CTS:  Carpal tunnel syndrome (see above).
Cubital:  1. Pertaining to the elbow. 2. Pertaining to the forearm and hand. 3. Pertaining to the ulna. From the Latin cubitum meaning elbow or cubit. The cubit was a unit of length based on the length of the forearm from the elbow to the tip of the middle finger.
Cubital tunnel:  The opening between the two heads of a muscle through which the ulnar nerve passes at the elbow and enters the forearm. (The muscle is called the flexor carpi ulnaris.) Compression of the ulnar nerve in this passageway results in the cubital tunnel syndrome.
Cubital tunnel syndrome:  A form of mononeuropathy due to compression or other injury of the ulnar nerve at the elbow. Symptoms of the cubital tunnel syndrome may include pain and numbness along the ulnar aspect of the hand and forearm (the little finger side), and weakness of the hand.
Cubitus:  1. The elbow. 2. The forearm and hand. 3. The ulna. From the Latin cubitus meaning elbow. The adjective is cubital.
Cubitus valgus:  A deformity of the elbow resulting in an increased carrying angle (so that, with the arm extended at the side and the palm facing forward, the forearm and hand are held at greater than 15 degrees away from the side of the body). Cubitus valgus can be due to a congenital malformation, as in Turner syndrome and Noonan syndrome, or be due to a fracture. Cubitus is the Latin word for elbow and valgus means angled outward.
Cubitus varus:  A deformity of the elbow resulting in a decreased carrying angle (so that, with the arm extended at the side and the palm facing forward, the forearm and hand are held at less than 5 degrees). There is deviation of the forearm toward the midline of the body. Cubitus is the Latin word for elbow and varus means angled inward. Cubitus varus is also called the gun stock deformity.
Cuboid bone:  The cuboid bone is the outer bone in the instep of the foot. It is called the cuboid bone because it is shaped like a cube. The cuboid bone articulates posteriorly (it has a joint in back) with the calcaneus (the heel bone) and anteriorly (it has joints in front) with the 4th and 5th metatarsals (bones just behind the 4th and 5th toes).
Cul-de-sac:  A blind pouch or cavity that is closed at one end. One example is the appendix.
Culdocentesis:  The puncture and aspiration (withdrawal) of fluid from the cul-de-sac, the rectouterine pouch (the pouch of Douglas), an extension of the peritoneal cavity between the rectum and back wall of the uterus. The word "culdocentesis" is derived from "cul-de-sac" which is a blind pouch or cavity that is closed at one end and, in a more specific sense, refers to the rectouterine pouch. In French, "cul-de-sac" literally is "bottom of (a) sack." As early as the 13th century, a cul-de-sac was a dead-end street (or a dead-end way), a blind alley. A "centesis" is a puncture (the Greek kentesis = puncture).
Culdoscope:  The viewing tube (endoscope) introduced through the end of the vagina into the cul-de-sac. The cul-de-sac is also called the rectouterine pouch (the pouch of Douglas), an extension of the peritoneal cavity between the rectum and back wall of the uterus. This procedure is termed culdoscopy.
Culdoscopy:  The introduction of a viewing tube (called an endoscope or culdoscope) through the end of the vagina into the cul-de-sac. The cul-de-sac is also called the rectouterine pouch (the pouch of Douglas), an extension of the peritoneal cavity between the rectum and back wall of the uterus.
Culture:  The propagation of microorganisms in a growth media. Any body tissue or fluid can be evaluated in the laboratory by culture techniques in order to detect and identify infectious processes. Culture techniques also be used to determine sensitivity to antibiotics.
Cupping:  1. A cup-shaped depression, as in the head of the optic nerve in the eye. 2. Treatment in which a cup is attached to the skin surface, usually on the back and the air within the cup is evacuated to suck the skin in and increase local blood flow. The practice has numerous variations including burning alcohol or another substance within the cup to create the vacuum and increase the heat.
Curare:  A muscle relaxant used in anesthesia (and, in the past, in arrow poisons by South American Indians). Curare competes with acetylcholine, a chemical that carries information between nerve and muscle cells, and blocks transmission of the information. Curare thus produces paralysis and as a poison it kills by paralyzing the diaphragm resulting in asphyxiation.
Curcumin:  A mixture of compounds derived from the curry spice turmeric. Curcumin is sold in the US as a herbal supplement. It has been alleged to have antioxidant, antiviral, antiinflammatory, anticancer, and cholesterol-lowering effects. Preliminary studies suggest that curcumin may block the progression of multiple sclerosis in mice.
Curettage:  The removal of growths or other material from the wall of a cavity or other surface, as with a curet. A curet, or curette, is a spoon-shaped instrument with a sharp edge. The word "curette" comes from French and means a scraper. The verb "curer" means to scrape or clean. Curettage may, for example, be used to remove a skin cancer. After a local anesthetic numbs the area, the cancer is scooped out with a curette. Dilation and curettage (D & C) refers to dilation of the cervix (widening the cervix) and curettement of the endometrium (the lining of the uterus).
Curette:  A spoon-shaped instrument with a sharp edge. The word "curette" comes from the French and means a "scraper." The French verb "curer" is "to scrape clean."
Curettement:  Curettage (see above).
Curie (Ci):  A unit of radioactivity. (Specifically, the quantity of any radioactive nuclide in which the number of disintegrations per second is 3.7 X 10 to the 10th). Named for Marie and Pierre Curie who did pioneering research in radioactivity, distinguished alpha, beta, and gamma radiation, discovered polonium and radium, and isolated pure radium. They shared the Nobel Prizes in Physics (with A.H. Becquerel) in 1903 and, after Pierre's death, Marie received the Nobel Prize in Chemistry in 1911.
Cushing syndrome:  The constellation of symptoms and signs caused by an excess of cortisol hormone. Cushing syndrome is an extremely complex hormonal condition that involves many areas of the body. Common symptoms are thinning of the skin, weakness, weight gain, bruising, hypertension, diabetes, thin weak bones (osteoporosis), facial puffiness and, in women, cessation of menstrual periods. Ironically, one of the most common causes of Cushing syndrome is the administration of "cortisol-like medications" for the treatment of diverse diseases. All other cases of Cushing syndrome are due to the excess production of cortisol by the adrenal gland as, for example, due to: An abnormal growth of the pituitary gland, which can stimulate the adrenal gland; a benign or malignant growth within the adrenal gland itself, which produces cortisol; or Production within another part of the body (ectopic production) of a hormone that directly or indirectly stimulates the adrenal gland to make cortisol. The neurosurgeon Harvey Cushing (1869-1939) described excessive production of cortisol by the adrenal gland due specifically to an ACTH-secreting pituitary adenoma, a benign pituitary tumor that puts out ACTH (AdrenoCorticoTropic Hormone). This drives the adrenal gland to overproduce cortisol.
Cushingoid:  Having the constellation of symptoms and signs caused by an excess of cortisol hormone: that is, Cushing syndrome. (see above)
Cutaneous:  Relating to the skin. From the Latin cutis meaning skin.
Cutaneous allodynia:  Pain resulting from an innocuous stimulus to normal skin or scalp. The stumulus that triggers allodynia is not normally painful. The pain can be provoked by combing or brushing the hair, shaving, showering, wearing glasses or earrings. The pressure of a single strand of hair reportedly can feel like a jab with a white-hot knife. Cutaneous allodynia is believed due to a transient increase in the responsiveness of central pain neurons that process information arising from the skin. It is commonly associated with migraine. From allo- meaning other + -dynia meaning pain.
Cutaneous papilloma:  A small tag of skin that may have a stalk (a peduncle). Cutaneous papillomas may appear on the skin almost anywhere although the favorite locales are the eyelids, neck, armpits (axillae), upper chest, and groin. Invariably benign, this tiny tumor of the skin usually causes no symptoms unless repeatedly irritated as, for example, by the collar. Treatment may be done by freezing with liquid nitrogen or by cutting off with a scalpel or scissors if the skin tag is irritating or cosmetically unwanted. Medically, a cutaneous papilloma is also called an acrochordon. But it is far better known as a skin tag.
Cutaneous syndactyly:  A condition in which fingers or toes are joined together, and the joining involves only the skin, not the bones. Cutaneous syndactyly is the opposite of bony syndactyly, in which the bones are of the digits are joined.
Cutis:  The skin.
Cutis anserina:  Better known as goose bumps, a temporary local change in the skin when it becomes rougher due to erection of little muscles, as from cold, fear, or excitement. The chain of events leading to this skin change starts with a stimulus such as cold or fear. That stimulus causes a nerve discharge from the sympathetic nervous system, a portion of the autonomic (involuntary) nervous system. The nerve discharge causes contraction of little muscles called the arrectores pilorum (the hair erector muscles). Contraction of these muscles elevates the hair follicles above the rest of the skin. And it is these tiny elevations we perceive as goose bumps.
Cutis laxa:  A dermatologic condition characterized by unusually loose skin which may hang in pendulous folds. Cutis laxa is usually a genetic disorder.
CVA (Cerebrovascular accident):  The sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A CVA is also referred to as a stroke. Symptoms of a stroke depend on the area of the brain affected. The most common symptom is weakness or paralysis of one side of the body with partial or complete loss of voluntary movement or sensation in a leg or arm. There can be speech problems and weak face muscles, causing drooling. Numbness or tingling is very common. A stroke involving the base of the brain can affect balance, vision, swallowing, breathing and even unconsciousness. A stroke is a medical emergency. Anyone suspected of having a stroke should be taken immediately to a medical facility for diagnosis and treatment.
CVC:  Commonly used abbreviation for a Central Venous Catheter, a catheter (tube) that is passed through a vein to end up in the thoracic (chest) portion of the vena cava (the large vein returning blood to the heart) or in the right atrium of the heart.
CVS:  1. Chorionic villus sampling, a procedure for first-trimester prenatal diagnosis. 2. Cyclic vomiting syndrome, also known as abdominal migraine (see below).
Cyanide:  Poisoning with cyanide, a rapidly acting, potentially deadly chemical that can exist as a colorless gas, such as hydrogen cyanide (HCN) or cyanogen chloride (CNCl), or a crystal form such as sodium cyanide (NaCN) or potassium cyanide (KCN). Cyanide sometimes is described as having a "bitter almond" smell, but it does not always give off an odor, and not everyone can detect this odor. Cyanide is naturally present in some foods and in certain plants such as cassava. Cyanide is contained in cigarette smoke and the combustion products of synthetic materials such as plastics. In manufacturing, cyanide is used to make paper, textiles, and plastics. It is present in the chemicals used to develop photographs. Cyanide salts are used in metallurgy for electroplating, metal cleaning, and removing gold from its ore. Cyanide gas is used to exterminate pests and vermin in ships and buildings. If accidentally ingested (swallowed), chemicals found in acetonitrile-based products that are used to remove artificial nails can produce cyanide. Hydrogen cyanide, under the name Zyklon B, was used as a genocidal agent by the Germans in World War II. People may be exposed to cyanide by breathing air, drinking water, eating food, or touching soil that contains cyanide. Cyanide enters water, soil, or air as a result of both natural processes and industrial activities. In air, cyanide is present mainly as gaseous hydrogen cyanide. Smoking cigarettes is probably one of the major sources of cyanide exposure for people who do not work in cyanide-related industries. Poisoning caused by cyanide depends on the amount of cyanide a person is exposed to and the route and duration of exposure. Breathing cyanide gas causes the most harm, but ingesting cyanide can be toxic as well. Cyanide gas is most dangerous in enclosed places where the gas will be trapped. Cyanide gas evaporates and disperses quickly in open spaces, making it less harmful outdoors. Cyanide prevents the cells of the body from getting oxygen. When this happens, the cells die. Cyanide is more harmful to the heart and brain than to other organs because the heart and brain use a great deal of oxygen. People exposed to a small amount of cyanide by breathing it, absorbing it through their skin, or eating foods that contain it may have some or all of the following symptoms within minutes: rapid breathing, restlessness, dizziness, weakness, headache, nausea and vomiting, and rapid heart rate. Exposure to a large amount of cyanide by any route may cause these other health effects as well: convulsions, low blood pressure (hypotension), slow heart rate (bradycardia), loss of consciousness, lung injury and respiratory failure leading to death. Survivors of serious cyanide poisoning may develop heart and brain damage.
Cyanosis:  A bluish color of the skin and the mucous membranes due to insufficient oxygen in the blood. For example, the lips may show cyanosis. Cyanosis can be evident at birth, as in a "blue baby" who has a heart malformation that permits blood that is not fully oxygenated to enter the arterial circulation. Cyanosis can also appear at any time later in life. The word "cyanosis" comes from the Greek "cyanos" meaning dark blue.
Cyclic vomiting syndrome (CVS):  A syndrome characterized by episodes, bouts, or cycles of severe nausea and vomiting that last for hours or even days and alternate with longer asymptomatic periods (with no symptoms). The cause of the syndrome is unknown. Each episode is similar to previous ones and tends to start at about the same time of day, last the same length of time, and present the same symptoms at the same level of intensity. Episodes of CVS can be so severe that a person may have to stay in bed for days, unable to go to school or work. Because other common diseases and disorders can also cause cycles of vomiting, people with the syndrome may initially be misdiagnosed. Age of onset: Cyclic vomiting syndrome (CVS) affects children more often than adults. It starts most commonly between ages 3 and 7. In adults, episodes tend to occur less often but last longer than in children and the events that trigger episodes in adults cannot be pinpointed as easily as they can in children.
Cyclin:  One of a group of proteins that regulate the cell cycle.
Cyclin D:  A family of three closely related proteins termed cyclin D1, D2 and D3 that are expressed in an overlapping redundant fashion in all proliferating cell types and collectively control the progression of cells through the cell cycle. Since the D-cyclins are essential to cell division, they may also be involved in cancer.
Cyclin E:  A protein that is part of a molecular network that controls the cell cycle. Cyclin E is of prognostic value in breast cancer. High levels of cyclin E in the tumor correlate with a poor outcome, whereas low levels correlate with a good outcome.
Cyclooxygenase:  Abbreviated cox. See above: Cox-1; Cox-2.
Cyclooxygenase inhibitor:  See above: Cox-1 inhibitor; Cox-2 inhibitor.
Cyclopia:  A congenital abnormality (birth defect) in which there is only one eye. That eye is centrally placed in the area normally occupied by the root of the nose. There is a missing nose or a nose in the form of a proboscis (a tubular appendage) located above the eye. Cyclopia and milder forms of the same developmental disorder result from holoprosencephaly which is a failure of the embryonic forebrain to subdivide properly. (The embryonic forebrain is normally responsible for inducing the development of the orbits.) Chromosome abnormalities (such as trisomy 13) and gene mutations can disrupt this process. So also can certain toxins, some of them found in wild plants. The term "cyclopia" comes from the Cyclops, the one-eyed giants of Greek mythology, a mythical race of lawless giant shepherds who lived in Sicily. They had a single large round eye in the center of the forehead. The word "cyclops" itself comes from the Greek "kyklos" (circle) + "ops" (eye). Cyclopia is also called synophthalmia.
Cyclops:  A common freshwater crustacean. Some species of Cyclops serve as hosts for parasites such as the guinea worm, the cause of dracunculiasis (guinea worm disease).
Cyclospora infection:  Infection with Cyclospora cayetanensis, a single-celled parasite. The first known human cases of illness caused by Cyclospora were reported in 1979. More recently, outbreaks of cyclosporiasis have been reported in the US and Canada. Cyclospora is spread by people ingesting water or food that was contaminated with infected stool. Outbreaks of cyclosporiasis have been linked to various types of fresh produce.
Cyclosporiasis:  Infection with the parasite Cyclospora cayetanensis.
Cyclothymia:  A form of bipolar disorder in which the mood swings are less severe.
Cylindroma:  A benign tumor of skin adnexa such as the sweat gland, arising as a nodule on the scalp and, less often, the face or limbs. Cylindromas may cover the scalp and so are called turban tumors. See: Familial cylindromatosis below.
Cynophobia:  An abnormal and persistent fear of dogs. Sufferers from cynophobia experience anxiety even though they realize that most dogs pose no threat. To avoid dogs, they may barricade yards or refuse to travel except in an enclosed vehicle. "Cynophobia" is derived from the Greek "kyon" (dog) and "phobos"(fear).
Cyst:  A cyst is an abnormal, closed sac-like structure within a tissue that contains a liquid, gaseous, or semisolid substance. A cyst can occur anywhere in the body and can vary in size. The outer, or capsular, portion of a cyst is termed the cyst wall.
Cystectomy:  Surgery to remove the bladder.
Cysteine:  An amino acid, one of the 20 building blocks of protein. Cysteine can be synthesized by the body and is therefore not "essential" to (not necessary to be in) the diet.
Cystic acne:  This is a type of localized infection (abscess) formed when oil ducts become clogged and infected. Cystic acne is most common in the teenage years.
Cystic fibrosis:  A common genetic disease inherited as a recessive condition. Thick mucus can clog the lung passages and block the ducts of the pancreas in cystic fibrosis. Cystic fibrosis: One of the most common grave genetic (inherited) diseases, CF affects the exocrine glands and is characterized by the production of abnormal secretions, leading to mucous build-up. This accumulation of mucus can impair the pancreas and, secondarily, the intestine. Mucous build-up in lungs tends progressively to impair respiration. Without treatment, CF results in death for 95% of affected children before age 5. However, with diligent medical care patients with CF are surviving even beyond middle age. Early diagnosis of CF is of great importance. Early and continuing treatment of CF is essential for long-term survival. However, as more people with CF survive childhood, new problems are emerging. For example, 68% of 75 adult women with CF reported leakage of urine within the past year. Coughing, sneezing, laughing and airway clearance provoked the leakage, which was worse when their chest disease was most severe. CF is inherited in an autosomal recessive manner and affects both boys and girls. One in 400 white couples is at risk for having children with CF and their risk with each pregnancy is 1 in 4, so (multiplying 1 in 400 times 1 in 4) the overall risk that their child will have CF is 1 in 1600. Note that once a couple has had a CF child, the risk that each of their subsequent children will have CF drops to 1 in 4 (25%). The treatment of CF includes physical therapy to loosen the mucus in the lungs, pancreatic enzymes, and medications to fight dangerous infections of the lungs. CF is caused by mutation in the gene encoding CFTR (cystic fibrosis conductance regulator) on chromosome 7. The most common mutation, DeltaF508, results in the production of a misfolded CFTR protein that is retained in the endoplasmic reticulum and targeted for degradation.
Cystic hernia:  Bulging of the bladder into the vagina. From cysto- (the bladder) + -cele (hernia) because the bladder herniated into the vagina. Also called a cystoceoel.
Cystic periventricular leukomalacia:  Softening of the white matter near the ventricles of the brain resulting in abnormal cysts. Cystic periventricular leukomalacia is a major problem in very premature infants. Treating the mother with a cortisone-like drug before the premature birth has been discovered to protect the baby's brain from this complication. Probably a better preventive, in this writer's esimation, would be regular doses of DHA and B complex vitamins. However, this needs study and should not be taken as medical advice at this time.
Cysticercosis:  An infection caused by the pork tapeworm, Taenia solium. Infection occurs when the tapeworm larvae enter the body and form cysticerci (SIS-tuh-sir-KEY) (cysts). When cysticerci are found in the brain, the condition is called neurocysticercosis (NEW-row SIS-tuh-sir-KO-sis). Cysticercosis is contracted by swallowing pork tapeworm eggs. The tapeworm that causes cysticercosis is found worldwide. Infection is found most often in rural, developing countries with poor hygiene where pigs are allowed to roam freely and eat human feces. This allows the tapeworm infection to be completed and the cycle to continue. Infection can occur, though rarely, if you have never traveled outside of the United States. Taeniasis and cysticercosis are very rare in Muslim countries and in Israel where eating pork is forbidden and discouraged respectively.
Cysticercus:  The larval form of any of the Taenia tapeworms. The plural is cysticerci. Infection with cysticerci is referred to as cysticercosis.
Cystine:  (pronounced sis-stein) An amino acid that is particularly notable because it is the least soluble of all of the naturally occurring amino acids and because it precipitates out of solution in the genetic disease cystinuria to form stones in the urinary tract. Cystine is the chief sulfur-containing compound in protein. Cystine is generated by the union of two cysteine (pronounced sis-teen) molecules and so is sometimes called dicysteine. It is abbreviated Cys-Cys.
Cystine kidney stones:  Cystine kidney stones are due to cystinuria, an inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine that results in an excess of cystine in the urine (cystinuria) and the formation of cystine stones. Cystinuria is the most common defect in the transport of an amino acid. Although cystine is not the only overly excreted amino acid in cystinuria, it is the least soluble of all naturally occurring amino acids. Cystine tends to precipitate out of urine and form stones (calculi) in the urinary tract. Small stones are passed in the urine. However, big stones remain in the kidney (nephrolithiasis) impairing the outflow of urine while medium-size stones make their way from the kidney into the ureter and lodge there further blocking the flow of urine (urinary obstruction). Obstruction of the urinary tract puts pressure back up on the ureter and kidney causing the ureter to widen (dilate) and the kidney to be compressed. Obstruction also causes the urine to be stagnant (not moving), an open invitation to repeated urinary tract infection. The pressure on the kidneys and the urinary infections results in damage to the kidneys. The damage can progress to renal insufficiency and end-stage kidney disease, requiring renal dialysis or a transplant. The stone are responsible for all the signs and symptoms of cystinuria, including:Hematuria -- blood in the urine; Flank pain -- pain in the side, due to kidney pain; Renal colic - intense, cramping pain due to stones in the urinary tract; Obstructive uropathy -- urinary tract disease due to obstruction; and Urinary tract infections.
Cystine transport disease:  Commonly known as cystinuria, this is an inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine resulting in an excess of cystine in the urine (cystinuria) and the formation of cystine stones.
Cystinosis:  A genetic disease characterized by the widespread deposition of the amino acid cystine in cells due to a defect in cystine transport. (Cystine normally forms after protein degradation and is transported from structures called lysosomes into the cytoplasm. In cystinosis, cystine accumulates in the lysosomes and eventually forms crystals throughout the body. Cystinosis is therefore a lysosomal storage disease.) The disease is inherited in an autosomal recessive manner.
Cystinuria:  An inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine resulting in an excess of cystine in the urine (cystinuria) and the formation of cystine stones.
Cystitis:  Inflammation of the bladder. Cystitis can be due for example to infection from bacteria that ascend the urethra (the canal from the outside) to the bladder. Symptoms include a frequent need to urinate (urinary frequency), often accompanied by a burning sensation (dysuria). As cystitis progresses, blood may be observed in the urine (hematuria) and the patient may suffer cramps after urination. In young children, attempts to avoid the pain of cystitis can be a cause for daytime wetting (enuresis). Treatment includes avoiding irritants, such as perfumed soaps, near the urethral opening; increased fluid intake; and antibiotics. Untreated cystitis can lead to scarring and the formation of stones when urine is retained for long periods of time to avoid painful urination.
Cystocele:  Bulging of the bladder into the vagina. From cysto- (the bladder) + -cele (hernia) because the bladder herniated into the vagina. Also called a cystic hernia.
Cystoscope:  An optical instrument (a scope) that is inserted through the urethra into the bladder. A cystoscope has two ports. Aside from the optical port that permits one to see inside the bladder, there is an additional port in the instrument for insertion of various instruments designed for biopsy (removal of tissue samples), treatment of small bladder tumors, removal of stones from the bladder, and removal of the prostate (prostatectomy).
Cystoscopy:  A procedure in which the doctor inserts a lighted instrument called a cystoscope into the urethra (the tube that carries urine from the bladder to the outside of the body) in order to look inside the urethra and bladder.
Cysts:  Cysts are abnormal, closed sac-like structures within a tissue that contain a liquid, gaseous, or semisolid substance. Cysts can occur anywhere in the body and can vary in size.
Cytogenetics:  The study of chromosomes, the visible carriers of DNA, the hereditary material.
Cytokine:  A small protein released by cells that has a specific effect on the interactions between cells, on communications between cells or on the behavior of cells. The cytokines includes the interleukins, lymphokines and cell signal molecules, such as tumor necrosis factor and the interferons, which trigger inflammation and respond to infections.
Cytokinesis:  During cell division, the process that partitions the cellular contents including the chromosomes, cytoplasm, and organelles into the two daughter cells. Cytokinesis occurs just after the segregation of the duplicated genome.
Cytomegalovirus (CMV):  A virus that infects 50-85% of adults in the US by age 40 and is also the virus most frequently transmitted to a child before birth. Persons with symptoms have a mononucleosis-like syndrome with prolonged fever and mild hepatitis. Once a person becomes infected, the virus remains alive and usually dormant within that person's body for life. Recurrent disease rarely occurs unless the person's immune system is suppressed due to therapeutic drugs or disease. CMV infection is therefore a concern because of the risk of infection to the unborn baby, people who work with children, and immunodeficient people such as transplant recipients and those with HIV. CMV is a member of the herpesvirus group, which also includes herpes simplex virus, varicella-zoster virus (which causes chickenpox) and Epstein-Barr virus (which causes infectious mononucleosis). These viruses share a characteristic ability to remain dormant within the body over a long period.
Cytoplasm:  All of the substance of a cell outside of the nucleus. The cytoplasm contains a number of different types organelles such as the mitochondria. Most, but not all, cells have cytoplasm. Mature sperm are essentially devoid of cytoplasm.
Cytoplasm:  All of the substance of a cell outside of the nucleus. The cytoplasm contains a number of different types organelles such as the mitochondria. Most, but not all, cells have cytoplasm. Mature sperm, for example, are essentially devoid of cytoplasm.
Cytoplasm:  All of the substance of a cell outside of the nucleus. The cytoplasm contains a number of different types organelles such as the mitochondria. Most, but not all, cells have cytoplasm. Mature sperm, for example, are essentially devoid of cytoplasm.
Cytosine (C):  One member of the G-C (guanine-cytosine) pair of bases in DNA.
Cytosine (C):  One member of the G-C (guanine-cytosine) pair of bases in DNA.
Cytoskeleton:  The scaffolding structure of the cell cytoplasm. The cytoskeleton consists of intermediate filaments, actin filaments, and microtubules.
Cytoskeleton:  The scaffolding structure of the cell cytoplasm. The cytoskeleton consists of intermediate filaments, actin filaments, and microtubules.
Cytotoxic:  Toxic to cells, cell-toxic, cell-killing. Any agent or process that kills cells. Chemotherapy and radiotherapy are forms of cytotoxic therapy. They kill cells.
Cytotoxic:  Toxic to cells, cell-toxic, cell-killing. Any agent or process that kills cells. Chemotherapy and radiotherapy are forms of cytotoxic therapy. They kill cells.
Cytotoxic T-lymphocyte:  A T cell that is antigen-specific and is able to search out and kill specific types of virus-infected cells. When cytotoxic T-lymphocytes (CTLs) find cells carrying the viral peptide they are looking for, they induce these cells to secrete proteins that attract nearby macrophages (a type of white blood cells). These macrophages then surround and destroy the infected cells. CTLs are important in the body's response to viruses and cancer.
Cytotoxic T-lymphocyte:  A T cell that is antigen-specific and is able to search out and kill specific types of virus-infected cells. When cytotoxic T-lymphocytes (CTLs) find cells carrying the viral peptide they are looking for, they induce these cells to secrete proteins that attract nearby macrophages (a type of white blood cells). These macrophages then surround and destroy the infected cells. CTLs are important in the body's response to viruses and cancer.



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