An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word “aneurysm” comes from the Greek aneurysma meaning ”a widening.“
An abdominal aneurysm is situated within the abdomen, usually involving the abdominal aorta, the large vessel coming directly from the heart. The full term for his condition is abdominal aortic aneurysm. Because of the volume of blood flowing under relatively high pressure within the aorta, a ruptured aneurysm of the aorta is a catastrophe usually resulting in death.
An arterial aneurysm involves an artery. As opposed to a venous aneurysm or a cardiac aneurysm.
An atherosclerotic aneurysm occurs because the vessel wall is weakened by atherosclerosis (not arteriosclerosis as arteriosclerosis does not cause aneurysms).
A berry aneurysm looks like a berry and classically occurs at the point at which a cerebral artery departs from the circular artery (the circle of Willis) at the base of the brain. It is also called a brain aneurysm, berry aneurysms often rupture and bleed. Survival from a ruptured berry aneurysm is about 50% and usually involves some serious neurological loss. Immediate surgical intervention is usually necessary.
A cardiac aneurysm is the bulging of an abnormally thin portion of the heart wall. It is also called a heart aneurysm.
In a dissecting aneurysm the wall of an artery rips (dissects) longitudinally, splitting the layers of the artery. This occurs because bleeding into the weakened wall splits the wall. Dissecting aneurysms tend to affect the thoracic aorta. They are particularly common in Marfan’s disease and in any case are often fatal. When they involve large vessels they require immediate surgical intervention. This is how Albert Einstein died at the age of 75.
A fusiform aneurysm is shaped like a spindle. It is a fusiform widening of an artery or vein. The word “fusiform” comes from the Latin fusus meaning “spindle.”
A milliary aneurysm is shaped like a millet seed. (Millet is a cereal grass. Its seed is about 2 millimeters in diameter.) Miliary aneurysms tend to affect minute arteries in the brain and, in the eye, the retina.
A racemose aneurysm which looks like a bunch of grapes. From the Latin racemus meaning “a cluster or bunch, particularly of grapes.”
A renal aneurysm involves a kidney.
A saccular aneurysm resembles a small sack. From the Latin sacculus meaning a small pouch. A berry aneurysm is typically saccular.
A thoracic aneurysm is located in the thorax (chest).
A venous aneurysm involves a vein as opposed to an arterial aneurysm or a cardiac aneurysm.