Blood flow to the legs (and sometimes the arms) can be reduced when their arteries are affected by peripheral arterial disease (PAD). Narrowing of the peripheral arteries occurs because of buildup of plaque (a mixture of fat, cholesterol, blood platelets, and blood vessel wall damage) within the arteries themselves. Plaque can block blood flow partially or totally. Poor circulation due to PAD can cause leg pain with walking and poor wound healing, which decrease quality of life and may lead to severe complications such as leg amputation. PAD is associated with several chronic medical problems, such as diabetes, high blood pressure, and high cholesterol. Persons who smoke have a much higher chance of developing PAD. Having PAD may signal the presence of heart disease, cerebrovascular (blood vessels in the brain) disease, or major arterial disease (thoracic or abdominal aortic aneurysms). It is important to understand that vascular disease anywhere is a marker for blood vessel disease in all other parts of the body. The January 14, 2009, issue of JAMA includes an article about exercise to treat peripheral arterial disease.