When Linda Molnar developed pain in her legs that got worse when she walked even a short distance, doctors initially attributed it to an old back injury. But three years and many doctor visits later, a vascular specialist finally gave her the correct diagnosis last fall: peripheral artery disease.

Often referred to as poor circulation, peripheral artery disease, or PAD, is a potentially fatal blockage of large arteries in the legs caused by the same kind of fatty deposits or plaque that can build up in the coronary arteries leading to the heart. Between eight and 12 million Americans have PAD, federal data show. By some estimates, those ranks could double in the next decade as the population ages and as diabetes and obesity