Bulimia nervosa is an eating disorder characterized by episodes of binge eating—consuming a lot of food quickly—followed by compensatory behavior, most commonly vomiting or "purging." People who are bulimic often feel a lack of control over their eating. A bulimic can consume as many as 3,400 calories in little more than an hour and as many as 20,000 calories in eight hours.
People with bulimia often know they have a problem and are afraid of their inability to stop eating. Bingeing is then followed by purging — namely, self-induced vomiting or the abuse of diuretics or laxatives. Bingeing and purging are often performed in secret, with feelings of shame alternating with relief.
Unlike those with anorexia, people with bulimia can maintain a normal weight for their age. But like people with anorexia, they often fear gaining weight, want desperately to lose weight, and are intensely unhappy with their body size and shape, which may explain why bulimic behavior often takes place in secret. The bingeing and purging cycle is usually repeated several times a week. As with anorexia, people with bulimia often have coexisting psychological illnesses, such as depression, anxiety, and substance abuse problems. Many physical dysfunctions result from the purging, including electrolyte imbalances, gastrointestinal troubles, and dental problems.
An estimated one to four percent of females have bulimia nervosa during their lifetime. The prevalence in males is unknown, but bulimia nervosa is far less common in males than females. Most cases begin in the late teens and early 20s, but can go undetected until the 30s or 40s.
According to DSM-5, common symptoms of bulimia nervosa include:
- Recurrent episodes of binge eating, characterized by eating within a discrete period of time — say, two hours — an amount of food substantially larger than most people would eat
- A feeling that one cannot stop eating or control what or how much one eats
- Recurrent compensatory behavior to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; and excessive exercise
- Self-evaluation unduly influenced by body shape and weight
- Does not occur exclusively with anorexia nervosa
- Chronically inflamed and sore throat
- Swollen glands in the neck and below the jaw
- Worn tooth enamel and increasingly sensitive and decaying teeth as a result of exposure to stomach acids
- Acid reflux disorder (gastroesophageal reflux disorder, or GERD)
- Intestinal distress and irritation from laxative abuse
- Kidney problems from diuretic abuse
- Severe dehydration from the purging of fluids
Bulimia is categorized as mild, moderate, severe, or extreme based on the number of inappropriate compensatory behaviors that happen each week.
Bulimia is more than just a problem with food. A binge can be triggered by dieting, stress, or uncomfortable emotions, like anger or sadness. Purging and other actions to prevent weight gain are ways for people with bulimia to feel more in control of their lives and to ease stress and anxiety. There is no single known cause of bulimia, but there are some factors that may play a part.
- Culture. Women in the U.S. are under constant pressure to fit a certain ideal of beauty. Images of flawless, thin females everywhere make it hard for women to feel good about their bodies. Increasingly, men are also feeling pressure to have a perfect body.
- Families. Those with a mother or sister who has bulimia are more likely to have bulimia. Parents who think looks are important, diet themselves, or criticize their children's bodies are more likely to have a child with bulimia.
- Life changes or stressful events. Traumatic events, like rape, as well as stressors, such as starting a new job, can trigger bulimia.
- Personality traits. Those with bulimia may have low self-esteem and feel hopeless. They may be very moody and have difficulty expressing anger or controlling impulsive behaviors.
- Biology. Genes, hormones, and other biological factors may contribute to developing bulimia.
As with anorexia, treatment for bulimia often involves a combination of options and depends on individual needs.
To reduce or eliminate bingeing and purging, a patient may undergo nutritional counseling and psychotherapy, especially cognitive-behavioral therapy, and be prescribed medication. Some antidepressants—such as fluoxetine (Prozac), the only medication approved by the FDA for treating bulimia—may help patients who also suffer from depression and anxiety. The drug also appears to help reduce binge-eating and purging as well as the chance of relapse, and it can improve eating attitudes.
Cognitive-behavioral therapy tailored to the treatment of bulimia has also been shown to be effective in changing bingeing and purging behavior and improving attitudes towards eating. Therapy may be done one-on-one or in a group setting.
Eating disorders are complex and challenging, and behavioral, psychological, and neuroscience research on eating disorders is ongoing into causes and treatments. Researchers are also working to define the basic processes involved in the disorders, to understand risk factors, to identify biological markers of the disorder, and to develop medications that target specific pathways affecting eating behavior. Neuroimaging and genetic studies may provide clues for individual responses to specific treatments.