There are four basic criteria for the diagnosis of Anorexia Nervosa that are characteristic:

1. The refusal to maintain body weight at or above a minimally normal weight for age and height.  Body weight less than 85% of the expected weight is considered minimal.
2. An intense fear of gaining weight or becoming fat, even though the person is underweight.
3. Self-perception that is grossly distorted and weight loss that is not acknowledged.
4. In women who have already begun their menstrual cycle, at least three consecutive periods are missed (amenorrhea), or menstrual periods occur only after a hormone is administered.

The DSM-IV further identifies two subtypes of Anorexia Nervosa.  In the binge-eating/purging type, the individual regularly engages in binge eating or purging behavior which involves self-induced vomiting or the misuse of laxatives, diuretics, or enemas during the current episode of anorexia.  In the restricting type, the individual severely restricts food intake but does not engage in the behaviors seen in the binge eating type.