Anorexia nervosa is an eating disorder in which a person has an aversion to food that results in starvation and an inability to stay at the minimum body weight considered healthy for their age and height.

Persons with this disorder may have an intense fear of weight gain, even when they are underweight. Not eating enough food or exercising too much results in severe weight loss.

See also:

• Bulimia
• Intentional weight loss

The exact causes of anorexia nervosa are unknown. Genetics and social attitudes towards body appearance may play a role. Some experts have suggested that conflicts within a family may contribute to this eating disorder.

Anorexia is eight times more common in people who have relatives with the disorder.

Risk factors include:

• Being female
• Eating and gastrointestinal problems during early childhood
• Childhood anxiety
• Increased concern or attention to weight and shape
• Negative self-image
• Accepting societal attitudes towards thinness
• Perfectionism and other personality traits

Anorexia nervosa usually occurs in adolescence or young adulthood. It is more common in females. The eating disorder is seen mainly in Caucasian women who are high academic achievers and have a goal-oriented family or personality.

A person with anorexia may severely limit the amount of food they eat, or eat and then make themself throw up. They may also use diuretic (water) pills and laxatives to lose weight.

Most individuals with anorexia nervosa do not recognize that they have an eating disorder.

Behaviors that may be noticed in a person with anorexia may include:

• Going to the bathroom right after meals
• Quickly eating large amounts of food
• Compulsive exercising
• Cutting food into small pieces
• Restricting how much food they eat
• Inappropriate use of laxatives, enemas, or diuretics (water pills) in an effort to lose weight

Symptoms may include:

• Extreme weight loss (15% or greater below the expected weight)
• Wasting away of muscle and loss of body fat
• Poor memory or poor judgement
• Confused or slow thinking
• Very sensitive to cold (wearing several layers of clothing to stay warm)
• No menstruation
• Low blood pressure
• Dental cavities due to self-induced vomiting
• Dry mouth
• Blotchy or yellow skin
• Fine hair
• Depression

A diagnosis of anorexia nervosa is not made until other causes of weight loss are ruled out. For example, extreme weight loss could be due to celiac disease, inflammatory bowel disease, Addison's disease, and many other metabolic, endocrine, digestive, or nervous system disorders.

Tests will be done to help determine the cause of weight loss or to determine what damage the weight loss has caused cause. They may include:

• CHEM-20
• ECG
• LH response to GnRH
• Urinalysis
• Thyroid function tests

The biggest challenge in treating anorexia nervosa is having the person recognize that their eating behavior is itself a problem, not a solution to other problems. However, most persons with anorexia nervosa deny that they have an eating disorder. Individuals often enter treatment when their condition is fairly advanced.

The goal of treatment is first to restore normal body weight and eating habits, and then attempt to resolve psychological issues.

A hospital stay may be needed if:

• The person has lost a lot of weight (below 30% of their ideal body weight for their age and height)
• Weight loss continues despite treatment
• Medical complications, such as heart rate problems, changes in mental status, low potassium levels, or mental status problems, develop
• The person has severe depression or thinks about committing suicide

Other treatment may include:

• Antidepressant drug therapy for depression
• Behavioral therapy
• Psychotherapy
• Supportive care

Severe and life-threatening malnutrition may require feedings through a vein.

See: Eating disorders - support group

Anorexia nervosa is a serious and potentially deadly medical condition. By some estimates, it leads to death in 10% of cases. Experienced treatment programs have a good success rate in restoring normal weight, but relapse is common.

Women who develop this eating disorder at an early age have a better chance of complete recovery. However, most people with anorexia will continue to prefer a lower body weight and be preoccupied with food and calories to some extent. Weight management may be difficult, and long-term treatment may be necessary to help maintain a healthy body weight.

Complications can be severe. A hospital stay may be needed.

Complications may include:

• Severe dehydration, possibly leading to shock
• Electrolyte imbalance (such as potassium insufficiency)
• Cardiac arrhythmias
• Severe malnutrition
• Thyroid gland deficiencies which can lead to cold intolerance and constipation
• Appearance of fine baby-like body hair (lanugo)
• Bloating or edema
• Decrease in white blood cells which leads to increased susceptibility to infection
• Osteoporosis
• Tooth erosion and decay
• Seizures related to fluid shifts due to excessive diarrhea or vomiting

Talk to your doctor if your child is restricting his or her food intake, over-exercising, or is excessively preoccupied with weight. Getting early medical help before abnormal patterns are established can reduce the severity of an eating disorder.

In some cases, prevention may not be possible. Encouraging healthy, realistic attitudes toward weight and diet may be helpful. Sometimes, counseling can help.

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