Peripheral arterial disease (PAD) is an ongoing condition that results from narrowing or blockage of the arteries that supply oxygen-rich blood to the legs, abdomen, pelvis, arms, or neck. The most common cause of this disease is the buildup of excess cholesterol, calcium, and other substances (plaque) on the inside of arteries, particularly those that feed the legs.

In peripheral arterial disease, the arteries harden and narrow (atherosclerosis), reducing blood flow to other parts of the body. As a leg artery narrows, the leg muscles do not get enough blood, especially during increased activity. When the muscle is in a resting state, the blood supply may be adequate.

The main symptom of peripheral arterial disease in the leg is a tight or squeezing pain in the calf, foot, thigh, or buttock that occurs during exercise (such as walking up a hill or a flight of stairs, running, or simply walking a few steps). This pain is called intermittent claudication. It usually happens after a certain amount of exercise and is relieved by rest. As the condition gets worse, leg pain may occur after only minimal activity or even when at rest.

Other signs of peripheral arterial disease in the legs include:

• Decreased leg strength and function and poor balance when standing.
• Cold and numb feet or toes.
• Sores that are slow to heal.

The first goal of treatment for peripheral arterial disease is to identify and change lifestyle factors, such as smoking, a high-fat diet, and lack of exercise, that may be causing the disease. Treatment may include cholesterol-lowering medicine and other medicines to lower the risk of heart attack and stroke. Surgery may be needed if blood flow is significantly decreased to some areas.