Anorexia simply means a loss of appetite. Anorexia nervosa is a psychological disturbance that is characterized by an intense fear of being fat. This persistent “fat image,” however untrue in reality, leads the patient to self-imposed starvation and emaciation to the point where one-third of the body weight is lost. Clinical diagnosis of anorexia is determined when patients weigh at least 15 percent less than the normal healthy weight for their height. Many patients do not maintain a normal weight because they refuse to eat enough or avoid eating, exercise obsessively, induce vomiting, and/or use laxatives or diuretics to lose weight. For women, this causes the menstrual period to stop.