Anorexia nervosa and bulimia nervosa are both eating disorders. Anorexia involves people who intentionally starve themselves when they are already underweight. Individuals with anorexia have a body weight that is 15 percent or more below recommended levels (as determined by a standard height-weight table). People suffering from this disorder have an intense fear of becoming fat, even when they are extremely underweight, and are usually unable to perceive their physical appearance accurately. Many females with anorexia stop having their menstrual cycle (period) for several months, a condition called amenorrhea.
By contrast, persons with bulimia nervosa consume large amounts of food during “binge” episodes in which they feel out of control of their eating. They try to prevent weight gain following such episodes by vomiting, using laxatives or diuretics, dieting or exercising aggressively. Persons with bulimia, like those with anorexia, are very dissatisfied with their shape and weight, and their self-esteem is unduly influenced by their appearance. To receive a formal diagnosis of bulimia nervosa, an individual must engage in binging and purging (vomiting, etc.) at least twice a week for three months. However, less frequent episodes of binging and purging may still be very upsetting and require professional assistance.
Anorexia and bulimia sometimes overlap. A minority of persons with anorexia engage in binge eating or purging. This contrasts with “restricting” anorexics who maintain their low body weight by dieting alone. If an individual binges and purges, but is 15 percent or more below recommended weight, then anorexia nervosa is the proper diagnosis.