The first victim of anorexia is often the bones. The disease usually develops in adolescence -- right at the time when young people are supposed to be putting down the critical bone mass that will sustain them through adulthood.
But the most life-threatening damage is usually the havoc wreaked on the heart. As the body loses muscle mass, it loses heart muscle at a preferential rate -- so the heart gets smaller and weaker. "It gets worse at increasing your circulation in response to exercise, and your pulse and your blood pressure get lower," says Mickley. "The cardiac tolls are acute and significant, and set in quickly." Heart damage, which ultimately killed singer Karen Carpenter, is the most common reason for hospitalization in most people with anorexia.