Most often, doctors use the term peripheral arterial disease to describe poor circulation in the arteries of the legs that results from atherosclerosis Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more 
. 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 Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more . Disorders that reduce blood flow of arteries in the abdomen are considered separately as abdominal aortic branch occlusion Abdominal Aortic Branch Occlusion Abdominal aortic branch occlusion is blockage or narrowing of one of the large arteries in the abdomen that come off of the aorta. Branches of the aorta can be blocked (occluded) due to atherosclerosis... read more .
Causes
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 Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more (hardening of the arteries). Fibromuscular dysplasia Fibromuscular Dysplasia Fibromuscular dysplasia is abnormal thickening of the walls of arteries that is not related to atherosclerosis or inflammation but that causes artery narrowing or blockage. Fibromuscular dysplasia... read more 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 Acrocyanosis Acrocyanosis, a functional peripheral arterial disease, is a persistent, painless bluish discoloration of both hands and, less commonly, of both feet, caused by spasm of the small blood vessels... read more 
, erythromelalgia Erythromelalgia Erythromelalgia is a rare syndrome in which small arteries (arterioles) of the skin dilate periodically, causing a burning pain, making the skin feel hot, and making the feet and, less often... read more , and Raynaud syndrome Raynaud Syndrome Raynaud syndrome, a functional peripheral arterial disease, is a condition in which small arteries (arterioles), usually in the fingers or toes, narrow (constrict) more tightly than normal in... read more 
are examples of functional peripheral vascular diseases.
