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Harvard Health Publications

Bulimia Nervosa

What Is It?

The main characteristics of the eating disorder, bulimia nervosa, are

  • Repetitive binge eating.

  • Compensatory behavior to prevent weight gain.

  • Exaggerated preoccupied with body shape and weight.

During a binge, a person eats large quantities of food in a relatively short time, regardless of hunger. Binge eating is defined only in part by food quantity. A more important feature is the person's state of mind: During a binge, the person with bulimia feels out of control of the eating and cannot stop it.

People with bulimia may try to control weight in a variety of ways. One strategy is purging (self-induced vomiting immediately after a binge). Another strategy is abuse of laxatives, suppositories, enemas or diuretics. Alternatively, a person may go on an extended fast or start a period of strenuous exercise.

There is significant overlap between bulimia nervosa and anorexia nervosa, since those with bulimia may restrict food intake (a characteristic of anorexia) and people with anorexia may binge and purge. In both disorders, a person may be preoccupied with weight and be very self-conscious about body size and shape.

When binge-eating occurs without the compensatory behaviors that are aimed at controlling weight, it is called binge-eating disorder.

The overwhelming majority of people with bulimia are female (85-90 percent) and the disorder usually begins between ages 15 and 20. The condition affects up to 4 percent of women at some point in life. When men have the disorder, it is usually the nonpurging type.

People with bulimia can eat huge quantities of food, sometimes up to 20,000 calories at a time. Binge foods tend to be "comfort" foods that are sweet, salty, soft or smooth, and generally high in calories. Examples are ice cream, cake and pastries.

People with bulimia may binge a few times a week or as frequently as several times a day. Although people with bulimia fear becoming fat, and some are severely underweight or overweight, most are of normal weight or only slightly overweight.

Like anorexia, bulimia is unhealthy for the body. Purging can cause dehydration. The strong acids in stomach contents eat away at the layer of protective tooth enamel, making teeth much more vulnerable to decay. Laxative use can cause chronic gastrointestinal problems. At its most destructive, bulimic behavior can lead to problems with heart function. Rarely, it can cause death.

People with bulimia often feel ashamed of their binging and purging behaviors, so they may act secretly. They often have other problems with impulse control (such as addictions) and other mental health problems, including depression, anxiety, panic, or social phobia.

The specific biological cause for bulimia nervosa is not known, but it is presumed to have a genetic (inherited) component. The disorder does run in families. Most experts believe that, in bulimia, the brain areas that regulate appetite do not function properly.


Symptoms of bulimia include:

  • Extreme concern over body weight or body shape.

  • Eating large quantities of food over a short period (binge eating), usually in secret.

  • Binge eating that is followed by self-induced vomiting, medication use (laxatives, diuretics, enemas or suppositories) or with fasting, restrictive dieting or excessive exercise.

Bulimia can lead to:

  • Apathy, poor concentration

  • Tooth erosion and decay

  • Constant sore throat

  • Muscle weakness

  • Bone pain with exercise

  • Low blood pressure

  • Irregular heartbeat

  • Swollen salivary glands

  • Constipation or other bowel problems

  • Gastrointestinal problems, such as bloating, heartburn or acid reflux

  • Fertility problems


The central characteristics of bulimia nervosa are binge eating and a preoccupation with weight or body image. Severe eating binges occur regularly, along with a sense of loss of control. The person performs compensating behavior such as purging, exercise or excessive dieting. See a doctor if you feel worried about such thoughts and behaviors connected to food and weight.

Your doctor will ask you about your medical history and do a physical examination to check your general health. She or he may also order blood tests to check for problems associated with vomiting or laxative use.

Your doctor will also explore whether you have any other areas of mental distress, such as obsessive-compulsive disorder, an anxiety or mood disorder, or problems with substance use.

Expected Duration

Bulimia can last for a short time, for example, during a period of stress or a life transition, or it can continue for many years. About a quarter of individuals with bulimia get better without treatment. With treatment, more than half improve.

But even after successful treatment, bulimia can return, which is why experts often recommend maintenance treatment. Estimates of frequency and severity vary widely.


There is no known way to prevent bulimia. Treatment can be easier if the problem is detected early.


An eating disorder is a complex mix of physical and emotional problems. Therefore, health care providers try to organize a treatment that can address these problems comprehensively.

The goals of treatment are to

  • help the patient meet her (or his) goals

  • reduce or eliminate binge eating and purging

  • treat any physical complications

  • provide education and motivate the individual to restore healthy eating

  • help the individual understand and change harmful thought patterns related to the disorder

  • identify and treat any associated mental disorders (for example, depression or anxiety)

  • encourage and develop family support

  • prevent relapse

Treatment includes nutritional counseling, psychological counseling or therapy, and medication such as antidepressants. It is often most helpful to combine a few of these approaches. As long as there is no acute medical danger, the person with bulimia should be encouraged to establish personal goals.

Nutritional counseling usually involves developing a structured meal plan and learning to recognize body cues and urges to binge and purge. A significant number of people with bulimia nervosa see improvements with relatively simple interventions, like being taught about the illness or using guided self-help programs.

Cognitive behavior therapy (CBT) is the best-studied approach, and it has proven to be effective. In general, psychotherapy aims to help people with bulimia improve their body image, understand and deal with their emotions, modify their obsessive thinking and compulsive behaviors related to food, and gain healthy eating behaviors.

To address the behavior, a CBT therapist may first teach about the illness itself, help plan regular meals, encourage monitoring of urges, and suggest ways to cope with them. On the cognitive side, the therapist will help the patient to understand stresses that trigger unhealthy eating and to modify attitudes and beliefs that contribute to the binge and purge cycle.

Family and group psychotherapy can be helpful, too. In practice, therapists tend to combine elements of CBT with other forms of therapy (for example, family counseling or therapy, interpersonal therapy and/or psychodynamic therapy) depending on the person's needs. Self-help groups and homework guided by a professional can also be good supplements to a treatment plan.

Medication can reduce the urge to binge and purge, particularly in the short term. But most patients are not able to manage an ongoing problem with medication alone. Therefore most experts recommend combining medication with psychotherapy or other kinds of support.

Fluoxetine (Prozac) has been most frequently studied medication and is effective. There is less evidence for other antidepressants. But alternatives are worth considering if a fluoxetine trial has not been helpful.

On average, doses for bulimia are higher than the average dose for depression, and more similar to the dose for obsessive-compulsive disorder. Because mood and anxiety disorders are often present, medication may be aimed specifically at those disorders.

When To Call a Professional

Contact a health care professional (physician, counselor, psychiatrist) if you have symptoms of bulimia. If you do not feel comfortable doing so, talk to a trusted friend or family member about your concerns and ask them to contact someone for you.

If someone you know shows signs of bulimia, gently encourage him or her to contact a physician or mental health professional. Given the common tendency to feel shame and the desire to keep the eating disorder a private matter, it is likely that the person will be reluctant to openly acknowledge the problem. Even so, non-judgmental prompting may nudge the person to seek help, even if they don't tell you about it. For more information on how to talk to someone you suspect is bulimic, see the Additional Information section below.


Many people with bulimia recover, especially if their condition is treated early. Unlike patients with anorexia nervosa, patients with bulimia are much less likely to require hospitalization. In long-term follow-up studies, as many as 70 percent of people with this disorder completely stop having bulimia symptoms. Some do continue to struggle with eating problems of varying degrees of severity.

Treatment improves chances of improvement. Prognosis is better if the illness starts in adolescence. Prognosis is worse if the person has other psychiatric problems, such as obsessive-compulsive disorder, a mood problem or a personality disorder, but outcomes are better in those cases if the person also gets treatment for those disorders.

External resources

National Association of Anorexia Nervosa and Associated Disorders

National Institute of Mental Health

American Psychiatric Association

American Psychological Association
