Usually, when one refers to peripheral vessels one is talking about those vessels that supply blood to our limbs. They arise as major branches of the large aorta vessel which is the main artery leaving the heart. Peripheral vascular disease refers to conditions that effect these vessels. The problem with the vessels may be either due to a mechanical blockage in the vessels or to a temporary narrowing in the vessel.
The usual problem is of a mechanical blockage in the vessel due to the condition atherosclerosis. Atherosclerotic plaques build up in the arteries supplying blood to the legs. If this plaque build up causes a major narrowing in the arteries, then when one walks a certain distance, there will not be enough blood to supply the leg muscles and one will experience a pain in the calf muscles. This pain goes away after one stops walking but returns again after walking about the same distance again. This condition is called intermittent claudication.
The condition is diagnosed by performing an arteriogram of the leg vessels. Treatment involves correcting any risk factors that make plaques worse such as smoking, diabetes, high blood cholesterol and high blood pressure. Your doctor may encourage you to try and walk as much as possible as this helps develop other little vessels in the leg which may help bring blood to the leg muscles. If you are very limited, your doctor may recommend surgery to try and clean out or bypass the narrowed leg arteries. There are some research observations that new vessel growth can be promoted in the legs by injecting a gene which switches on vessel growth. This is still in the experimental phase.
Functional peripheral vascular diseases In addition to the blockages in the arteries due to plaques, there are some individuals who develop problems due to spasm in the arteries. In this condition, the artery may look normal but goes into spasm which blocks off the blood supply to the legs for a short time. An example of this is Raynaud's disease (or Raynaud's phenomenon). It can be triggered by cold temperatures, emotional stress, work with vibrating machinery or smoking.