Many people worry about the potential life-threatening consequence of a heart attack, but do not realize that peripheral arterial disease (PAD), which occurs anywhere outside the heart, can be just as serious. The same plaque buildup that occurs in the coronary arteries can occur in any artery throughout the body. It is estimated that more than 12 million Americans have PAD, and of those, only 21% have actually been diagnosed. If a person has a history of heart disease, coronary artery disease or stroke, he or she has a one in three chance of also having PAD.