Functional peripheral arterial disease is much less common than occlusive peripheral arterial disease. Normally, the arteries of the arms and legs widen (dilate) and narrow (constrict) in response to changes in the environment, such as a change in temperature, changes in blood flow, or signals from the brain. Functional peripheral arterial disease usually occurs when the normal mechanisms that dilate and constrict these arteries are exaggerated. The affected arteries constrict more tightly and more often. These changes in constriction can be caused by
Functional peripheral arterial disorders include acrocyanosis, erythromelalgia, and Raynaud syndrome.