Peripheral arterial disease (PAD) is poor blood flow in your arteries. Your arteries carry blood to your organs and muscles. If arteries become narrowed or blocked because of disease, they cannot carry enough blood to allow your muscles and organs to work properly.

Peripheral arterial disease is also called peripheral vascular disease. This topic focuses on peripheral arterial disease of the legs, the area most commonly affected.

What causes PAD?

The most common cause of peripheral arterial disease is the buildup of plaque on the inside of arteries. Plaque is made up of extra cholesterol, calcium, and other material in your bloodstream. Over time, plaque builds up along the inner walls of the arteries, including those that supply blood to your legs.

If plaque builds up in your arteries, there is less room for blood to flow. Poor blood flow "starves" the muscles and other tissues in the lower body. See an illustration of peripheral arterial disease of the legs.

This process of plaque buildup—called atherosclerosis or "hardening of the arteries"—usually happens at the same time throughout the body. If you have hardening of the arteries in your legs, you most likely will have it in the arteries that supply blood to your heart and brain. These arteries are called coronary arteries and carotid arteries.

PAD increases your chance of having a heart attack or stroke. People with PAD are 3 to 4 times more likely to die from a stroke or heart attack than people of the same age who do not have PAD. 1

Atherosclerosis gradually develops over a lifetime, although symptoms typically do not occur until after age 65. High cholesterol, high blood pressure, and smoking contribute to atherosclerosis and peripheral arterial disease.

What are the symptoms?

The earliest and most common symptom is tight, aching, or squeezing pain in the calf, thigh, or rear end (buttock). This pain, called intermittent claudication, usually happens after you have walked a certain distance. For example, your pain may always start after you have walked a block or two or after a few minutes. The pain goes away if you stop. As PAD gets worse, you may have pain in your foot or toe when you are not walking.

Some people do not have any symptoms.

How is PAD diagnosed?

Your doctor will talk with you about your symptoms and medical history and will do a physical exam. During the exam, your doctor will check your pulses at your groin, behind your knee, on the inner ankle, and on the top of your foot. Your pulse shows the strength of blood flow. An absent or weak pulse is a sign of PAD. Your doctor may also look at the color of your foot when it is elevated and after exercise. The color of your foot can be a clue to whether enough blood is getting through your arteries.

You will likely have a test that compares the blood pressures in your legs with the blood pressure in your arms. This test is called an ankle-brachial index. You also may have another test called an arterial Doppler ultrasound to check the blood flow in your arteries.

You also might have blood tests to check your cholesterol and blood sugar. These tests will show whether you have other problems related to PAD, such as high cholesterol and diabetes.