Anorexia nervosa is one of the most common and most deadly eating disorders. Anorexia is characterized by a distorted body image, inadequate food intake, and significantly low body weight. Most people with anorexia have an intense fear of becoming fat or gaining weight. Few realize how sick they are.
Anorexia nervosa disorder is more common in girls than in boys and usually develops between 14 and 17 years of age. In the United States, anorexia nervosa is the third most common chronic illness among adolescents, and prevalence rates appear to be increasing. Currently, an estimated 1 out of 100 teens is affected and up to 13 percent have some symptoms but do not meet full criteria for diagnosis.
Anorexia nervosa usually takes one of two forms: the restricting subtype or the binge eating/purging subtype. The restricting subtype is characterized by maintaining a low weight by restricting caloric intake through dieting, fasting and/or excessive exercise. The binge-eating/purging subtype is characterized by having used self-induced methods within the past three months to get rid of calories, such as self-induced vomiting or habitual use of laxatives, enemas and/or diuretics.
Signs and symptoms of anorexia nervosa include the following:
- Body weight < 15 percent of expected or body mass index ≤ 17kg/m2
- Loss of menstruation (amenorrhea)
- Loss of muscle mass
- Low body temperature
- Low blood pressure
- Low resting heart rate
- The presence of fine thin hair (lanugo)
- Dry hair and skin
- Low bone mineral density (brittle bones)
- Dental caries
- Knuckle excoriations
- Parotid gland swelling for those who participate in the binging/purging subtype
About 70 percent of people with anorexia also have co-occurring disorders, which typically include depression, anxiety disorders, obsessive-compulsive disorders and social phobias. Patients with anorexia are also four times more likely to develop drug or alcohol use disorders. One in 5 anorexia nervosa deaths is by suicide.