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Anorexia Nervosa


Evelyn Attia

, MD, Columbia University Medical Center, New York State Psychiatric Institute;

B. Timothy Walsh

, MD, College of Physicians and Surgeons, Columbia University

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Anorexia nervosa is an eating disorder characterized by a relentless pursuit of thinness, a distorted body image, an extreme fear of obesity, and restriction of food consumption, leading to a significantly low body weight.





  • Treatments that emphasize returning to normal weight and normal eating behaviors (such as individual and family psychologic therapy) can help.

Anorexia nervosa usually begins during adolescence or young adulthood and rarely begins before puberty or after age 40. In a given year, up to 1 in 200 young females have anorexia nervosa. Anorexia nervosa is less common among males. However, mild cases may not be identified.


There are two types of anorexia nervosa:

  • Restricting type: People limit how much they eat but do not regularly binge eat or purge—for example, by making themselves vomit (called self-induced vomiting) or taking laxatives. Some exercise excessively.

  • Binge-eating/purging type: People restrict their food intake but also regularly binge eat and/or purge.

Did You Know?



What causes anorexia nervosa is unknown. Few risk factors for it, other than being female, have been identified.

Genetic and environmental (social) factors play a role in the development of anorexia nervosa. The desire to be thin pervades Western society, and obesity is considered unattractive by many. Even before adolescence, children are aware of these attitudes, and more than half of preadolescent girls diet or take other measures to control their weight. Yet only a small percentage of these girls develop anorexia nervosa.

Other factors, such as psychologic susceptibility, probably predispose certain people to develop anorexia nervosa. Many people who develop the disorder belong to middle or upper socioeconomic classes, are meticulous and compulsive, and have very high standards for achievement and success.


Anorexia nervosa may be mild and transient or severe and persistent.

The first indications of the impending disorder may be a subtle increased concern with diet and body weight. Such concerns seem out of place because most people who develop anorexia nervosa are not significantly overweight when the disorder begins. Preoccupation and anxiety about weight intensify as people become thinner. Even when emaciated, people may claim to feel fat, deny that anything is wrong, do not complain about weight loss, and usually resist treatment. They continue to try to lose weight even when friends and family members reassure them that they are thin or warn them that they are getting too thin. People with anorexia nervosa view any weight gain as an unacceptable failure of self-control.

Anorexia literally means lack of appetite, but most people who have anorexia nervosa are actually hungry. Many do not lose their appetite until they are very emaciated.

Also, people with this disorder are preoccupied with food. For example, they may do the following:

  • Rather than eat, they study diets and count calories.

  • They hoard, conceal, or throw away food.

  • They may collect recipes.

  • They may prepare elaborate meals for other people.


Most women with anorexia nervosa stop having menstrual periods, sometimes before losing much weight. Women and men with anorexia nervosa may lose interest in sex.



Depression is common.





Recognizing Anorexia Nervosa

People who have anorexia nervosa usually deny they have a problem and try to conceal their unusual eating habits rather than seek help. Because many people who have anorexia nervosa are meticulous, compulsive, and intelligent, with very high standards for achievement and success, they are often able to conceal the disorder. Thus, family members and friends may be unaware of the disorder until it has become severe.

Because anorexia nervosa has serious, sometimes life-threatening complications, family members and friends of someone who often diets or is excessively concerned about weight need to know how to recognize the disorder.

People with anorexia nervosa often do the following:

  • Complain about being fat although they are very thin

  • Deny being thin

  • Think about food all the time

  • Measure their food

  • Hoard, conceal, or throw away food

  • Prepare elaborate meals for others

  • Skip meals

  • Pretend to eat or lie about how much they have eaten

  • Exercise compulsively

  • Dress in bulky clothing or many layers

  • Weigh themselves several times a day

  • Base their self-esteem on how thin they are



  • Heart rhythm may become abnormal.

  • People may become dehydrated and prone to fainting.

  • Potassium and sodium levels in the blood may decrease.



  • A doctor's evaluation

  • Tests to check for problems due to anorexia nervosa


Doctors measure height and weight and use the results to calculate the body mass index. Doctors also ask people how they feel about their body and weight and whether they have other symptoms. Doctors may use questionnaires developed to detect eating disorders.


If people have the following, anorexia nervosa is more likely:

  • Restriction of eating that results in a low body weight, usually with a BMI of less than 17 (or for children, a BMI less than the 5th percentile for their age or less than what is expected based on prior growth—see CDC Growth Charts)

  • Fear of obesity




Did You Know?




With treatment, people with anorexia nervosa may have the following outcomes:






  • Measures to ensure that people consume enough calories and nutrients

  • Psychologic therapy

  • For adolescents, family therapy

  • Regular check-ups

Restoring body weight quickly is crucial when the following has happened:

  • Weight loss has been rapid or severe.

  • Weight has fallen below about 75% of the recommended body weight.

People with anorexia nervosa may need to be hospitalized to ensure that they consume enough calories and nutrients. Eating solid food is the best treatment, but sometimes liquid supplements are also given. Rarely, people who are severely undernourished or who resist eating food need to be fed through a tube inserted through their nose and down their throat into their stomach (nasogastric tube).

Doctors also treat any problems due to anorexia nervosa. For example, if bone density has been lost, people are given calcium and vitamin D supplements.




Psychotherapy is more effective for adolescents who have had the disorder for less than 6 months.


Treatment also involves seeing a doctor regularly for check-ups. Treatment often involves a team of health care practitioners, including a nutritionist, who may provide specific meal plans or information about the calories needed to restore weight to a normal level.


More Information


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