Peripheral artery disease (PAD) is the narrowing of arteries other than those leading to the brain or heart (the narrowing of these arteries are known as cerebrovascular disease and coronary artery disease respectively), resulting in circulatory problems. It occurs due to atherosclerosis, or the build-up of fatty plaque in the arteries. Peripheral artery disease may occur in any blood vessel but is more common in the legs than the arms. 

Common symptoms of peripheral artery disease are pain, aches and cramps the legs when walking or exercising, which diminish when resting. Other signs include muscle wasting, a change in the color of the legs, loss of hair, erectile dysfunction in men, smooth shiny skin, absence or faint pulse in the feet, loss of feeling in the toes, and sores or ulcers in the legs or feet that do not heal.

The likelihood of peripheral artery disease developing may be decreased by increasing physical activity levels, maintaining a healthy weight, stopping smoking, and taking steps to control high blood pressure, diabetes, and cholesterol levels. 

Treatment of the condition may require surgery, but it may also be treated with medication. Drug classes commonly used to treat peripheral artery disease are ADP (adenosine diphosphate) receptor antagonist platelet aggregation inhibitors, platelet camp enhancing platelet aggregation inhibitors, protease-activated receptor-1 (PAR-1) antagonist, and cerebral and peripheral vasotherapeutics excluding calcium antagonists with cerebral activity.