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 and is due to poor circulation of blood in the arteries of the legs. In 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, due to poor circulation to the penis. The usually intermittent nature of the pain is due to narrowing of the arteries that supply the legs with blood, limiting the supply of oxygen to the leg muscles, 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 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 and is exacerbated by cold weather (therefore worse in winger months). 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.