In peripheral arterial disease (previously called peripheral vascular disease), not enough blood flows to the legs. The condition usually is caused by fatty deposits called plaques that build up along the walls of blood vessels. This buildup shrinks the size of the passageway and reduces the amount of blood that can flow through. This is a condition called atherosclerosis.
The risk factors for getting peripheral arterial disease are similar to the risk factors for coronary heart disease, and include:
The most common symptom of peripheral arterial disease is intermittent claudication -- pain or cramping in the legs or buttocks that starts when you exercise and goes away when you rest. Often the pain is described as a deep ache, especially in the calf muscle. The pain may extend to the foot or up toward the thigh and buttock. Sometimes, there is just numbness in the leg or a sense that one leg gets tired when you walk. A foot or toes also may feel cold or numb.
If the arteries are severely narrowed, you could experience leg pain at rest, when you are not exercising. If blood flow stops completely (usually because a blood clot forms in the narrowed vessel), parts of the leg may become pale or turn blue, feel stone cold to the touch and eventually develop gangrene.
Your doctor will review your personal risk factors for atherosclerosis and your family history. Your doctor will ask if you or any family members have heart disease, high cholesterol, diabetes, kidney disease, high blood pressure or any other circulation disorder. During the physical examination, your doctor will feel the pulse in your upper leg (near the groin), on the inside of your ankle, the top of your foot and the back of your knee. Any weakness in a pulse may be a sign of narrowed arteries.
Usually the doctor can diagnose peripheral arterial disease based on your symptoms, risk factors, the examination of your legs and the strength of your pulses. Your doctor may measure the blood pressure in your legs and compare it to the blood pressure in your arm to calculate the ankle-brachial index, or ABI. The ratio the blood pressure measured at your ankle is compared to the blood pressure measured at your elbow. Normally blood pressure is the same or a little higher in the legs so the ratio is 1.0 or higher.
A ratio of less than 0.95 in either leg indicates narrowing of the arteries in that leg. People who have symptoms of peripheral arterial disease usually have a ratio of 0.8 or less.
Your doctor may order ultrasound of the legs to measure blood flow. The test is non-invasive and painless, using sound waves to create the pictures. If your doctor suspects that you need a procedure to help open a blocked blood vessel, you may need a magnetic resonance imaging (MRI) scan of your arteries or an angiogram, which is an X-ray test that uses dye in the narrowed arteries to reveal the pattern of blood flow and spot blockages.
Once you have peripheral arterial disease, your arteries usually will remain narrowed. However, even though your arteries are narrowed, your symptoms can decrease and even go away with treatment.
You can help to prevent peripheral arterial disease by modifying your risk factors:
Treatment for peripheral arterial disease includes:
Call your doctor if you consistently suffer from cramps, aching, numbness or disproportionate fatigue in your leg muscles or buttocks when you exercise. Call immediately if you have these symptoms at rest or when any part of your leg or foot suddenly turns numb, cold, pale or a bluish color.
In most people with peripheral arterial disease, leg symptoms remain stable. About 10% to 15% of patients improve, and about 15% to 20% get worse. The outlook is better for people who are able to remain tobacco-free, stay on a healthy diet, keep their blood cholesterol under control and exercise regularly.
National Heart, Lung and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD 20824-0105