Peripheral arterial disease (P.A.D.) occurs when plaque (plak) builds up in the arteries that carry blood to your head, organs, and limbs. Plaque is made up of fat, cholesterol, calcium, fibrous tissue, and other substances in the blood.
When plaque builds up in arteries, the condition is called atherosclerosis (ATH-er-o-skler-O-sis). Over time, plaque can harden and narrow the arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body.
P.A.D. usually affects the legs, but also can affect the arteries that carry blood from your heart to your head, arms, kidneys, and stomach. This article focuses on P.A.D. that affects blood flow to the legs.