Peripheral arterial disease (PAD) occurs when there is a narrowing of blood vessels outside the heart. The cause of PAD is atherosclerosis. This happens when the plaque, a substance made up of fat and cholesterol, builds up in the walls of the arteries that supply blood to the arms and legs. The plaque causes the arteries to narrow or become clogged. This may decrease or interrupt the flow of blood, usually to the legs, causing pain or numbness. When the obstruction of the blood flow is severe enough it can cause the death of the tissues. If these obstructions are not treated, it may be necessary to amputate the foot or leg.
A person with PAD also has an increased risk of heart attack, stroke, and transient ischemic attack. Often, buildup plaque in the arteries can be stopped or reversed with changes in diet, exercise and efforts to lower high cholesterol and high blood pressure.