P.A.D. occurs when extra cholesterol and other fats circulating in the blood collect in the walls of the arteries that supply blood to your limbs. This buildup—called plaque—narrows your arteries, often reducing or blocking the flow of blood.
P.A.D. is most commonly seen in the legs, but also can be present in the arteries that carry blood from your heart to your head, arms, kidneys and stomach. Nearly everyone who has P.A.D—even those who do not have leg symptoms—suffers from an inability to walk as fast, or as far, as they could before P.A.D.
The illustration shows an artery with normal blood flow (Figure A) and an artery containing plaque buildup (Figure B).