Anorexia nervosa is an eating disorder characterized by refusal to stay at even the minimum body weight considered normal for the person's age and height. Other symptoms of the disorder include distorted body image and an intense fear of weight gain.
Inadequate eating or excessive exercising results in severe weight loss. Eating disorders frequently develop during adolescence or early adulthood, but some reports indicate their onset can occur during childhood or later in adulthood. Anorexia nervosa is one of the two major types of eating disorders; the other is bulimia.
People with anorexia see themselves as overweight even though they are dangerously thin. The process of eating becomes an obsession to them. Unusual eating habits develop, such as avoiding what they perceive as high caloric food and meals, picking out a few foods and eating only these in small quantities, or carefully weighing and portioning food. People with anorexia may repeatedly check their body weight and many engage in other techniques to control their weight, such as intense and compulsive exercise or purging by means of vomiting and abuse of laxatives, enemas, and diuretics. Girls with anorexia often experience a delayed onset of their first menstrual period.