Bulimia nervosa, also known as bulimia and binge-purge syndrome, is an eating disorder that is characterized by a pattern of binge eating followed by harmful behaviors to control or prevent any resulting weight gain. Individuals with bulimia tend to associate their self-worth or self-esteem with the way their bodies look, and attempt to control their weight by purging. Bulimia may also be accompanied by abnormalities in mood and perception.

Eating – especially a healthy, well-balanced diet – is necessary for normal functioning of all organ systems. Disordered eating habits (e.g., skipping meals) or prolonged dieting (e.g., calorie restriction) may deplete the body of important nutrients. In some cases, such habits may become chronic and may lead to the development of an eating disorder, such as bulimia.

Binge eating is defined as the consumption of excessive amounts of food in a short time period, usually less than two hours. The food is often high in calories and easy to consume (e.g., ice cream, chips). The binging episodes are also accompanied by a sense of total lack of control. Individuals with bulimia often eat until they are uncomfortably, or even painfully full. Typically, people with bulimia purge themselves of eaten food by self-induced vomiting. The immediate effects of vomiting include relief from physical discomfort caused by the overeating and decrease in fear of gaining weight.

Patients with bulimia may rely on a variety of methods to induce vomiting, including the use of fingers or objects (e.g., pencils) to stimulate the gag reflex. People with bulimia often become so proficient at inducing vomiting, they eventually are able to throw up at will. Other purging methods include the misuse of laxatives (usually mild drugs used for inducing bowel movements) and diuretics. Rarely, people with bulimia rely on emetics (e.g., syrup of ipecac) to induce vomiting or enemas (injecting liquid into the intestines through the anus) for emptying the bowels.

Sometimes people with bulimia may fast for a few days or exercise excessively to compensate for binge eating. They may also rely on diet pills, cigarette smoking, amphetamines and caffeine (e.g., coffee, caffeinated diet drinks) to suppress hunger and/or boost energy. Prolonged use of these agents may result in tolerance and withdrawal symptoms.

Oftentimes, patients with bulimia feel ashamed of the eating problems and attempt to hide their behavior. They frequently eat in secrecy, or as inconspicuously as possible, and may hide food in strange places (e.g., under the bed) for later consumption. Bulimia binges are usually triggered by emotional stress, intense hunger following fasting or feelings related to body weight and shape or food. Following a binge, patients often experience depression and self-disgust.

Patients with bulimia frequently exhibit other types of psychological disorders including clinical depression and anxiety disorders (e.g., obsessive-compulsive disorder), which may also become exacerbated by the bodily effects of the eating disorder. Substance abuse or dependence – especially involving alcohol and stimulant drugs like cocaine (for appetite suppression) – is also prominent among people with bulimia. In severe cases, behavioral and emotional problems associated with this eating disorder may cause suicidal ideation.

Like most eating disorders, bulimia is more prevalent in females than males – especially adolescents and young adults – and is also more common in industrialized, economically developed nations. According to the U.S. National Institute of Mental Health (NIMH), an estimated 1 to 4 percent of females suffer from bulimia during their lifetime. The disorder is more common among males whose occupation or hobbies require gaining and/or losing weight rapidly, such as wrestlers and jockeys. However, because people with bulimia are typically within the normal weight range – although their weight may sometimes fluctuate – it may be difficult for others to recognize there is a problem and the eating disorder is believed to be underreported.