Body Dysmorphic Disorders can be defined by:

• Preoccupation with an imagined defect in appearance. If a slight physical anomaly is present, the person's concern is markedly excessive.

• The preoccupation causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

• The preoccupation is not better accounted for by another mental disorder (e.g., dissatisfaction with body shape and size in Anorexia Nervosa).

One variant of Body Dysmorphic Disorders is Megarexia, which can be seen as the opposite of Anorexia. While people with Anorexia sometimes wrongly think that they are fat even though they are thin, people with Megarexia wrongly think they are too thin, even though they are not. Megarexia is most common among young adults and body builders.