Q: Lately, I have noticed a pain in the calves of both legs after walking about a half-mile. After a short rest, the pain disappears and I can again walk for another half-mile before the pain occurs again. What could be causing this pain?
A: You have described the typical symptoms of intermittent claudication, characterized by pain in the muscles of the leg, especially the calf muscles, and caused by peripheral vascular disease (PVD). PVD in turn is caused by atherosclerotic narrowing of the large arteries supplying blood to arms and legs. The process is not unlike narrowing of the coronary arteries feeding the heart muscle.
Confirmation of the diagnosis and an assessment of the severity of the blockage can be done several ways. The simplest (and least useful) test is the strength of the pulses in your feet. More precise tests include comparing the blood pressure at several sites in the lower legs with blood pressure in the arms at rest and after exercise, measuring the velocity of blood flow in the arteries of the leg by ultrasound (Doppler ultrasound), and determining the time it takes for the pulse to reappear in the toe after a brief period of occlusion of a major artery.
The major risk factors for PVD are similar to those for coronary artery disease (CAD): smoking, high blood pressure, abnormalities of blood lipids and diabetes. Cigarette smoking is an especially great risk for CAD and PVD, but the effects of smoking differ in the two disorders. Whereas the risk for CAD tends to diminish once the habit is discontinued, the damage to peripheral blood vessels is permanent and related to duration and amount of smoking.
Other risk factors more prominent for PVD than for CAD are diabetes, as well as modest increases in blood glucose levels, elevated triglycerides and the low HDL cholesterol levels.
In the majority of people the symptoms of claudication remain relatively stable or progress quite slowly. In about one-third of those with claudication, however, symptoms become significantly worse, and gangrene-required amputation occurs in 1 percent to 5 percent of those with the most severe PVD.
The danger of amputation is particularly great in people with diabetes whose PVD is often accompanied by loss of sensation in the feet (peripheral neuropathy) with an increased tendency to superficial foot injuries that fail to heal properly due to the poor blood supply.
