Most often, doctors use the term peripheral arterial disease to describe poor circulation in the arteries of the legs that results from atherosclerosis. However, peripheral arterial disease can affect other arteries, such as those in the arms, and can have other causes. Disorders of arteries that supply the brain with blood are considered separately as cerebrovascular disease. Disorders that reduce blood flow of arteries in the abdomen are considered separately as abdominal aortic branch occlusion.
Peripheral arterial disease may be described as
Occlusive peripheral arterial disease is due to something that physically narrows or blocks arteries. The most common cause is atherosclerosis (hardening of the arteries). Fibromuscular dysplasia is another example of occlusive peripheral arterial disease.
In functional peripheral arterial disease, blood flow is decreased because the arteries do not function properly. Usually the dysfunction involves a sudden, abnormal contraction of the muscles (spasm) within the walls of the blood vessels. The spasm causes a temporary narrowing that reduces blood flow. More rarely, the condition is due to abnormal relaxation of the muscles within the walls of the blood vessels, leading to a widening (vasodilation) of arteries. Acrocyanosis, erythromelalgia, and Raynaud syndrome are examples of functional peripheral vascular diseases.