Bulimia nervosa is an eating disorder characterized by binge eating and engaging in inappropriate ways of counteracting the bingeing (using laxatives, for example) in order to prevent weight gain. The word "bulimia" is the Latin form of the Greek word bulimia, which means "extreme hunger." A binge is consuming a larger amount of food within a limited period of time than most people would eat in similar circumstances. Most people with bulimia report feelings of loss of control associated with bingeing, and some have mildly dissociative experiences in the course of a binge, which means that they feel disconnected from themselves and from reality when they binge.
Causes Of  Bulimia Nervosa

Erosion of tooth enamel because of repeated exposure to acidic gastric contents.

Dental cavities, sensitivity to hot or cold food.

Swelling and soreness in the salivary glands (from repeated vomiting).

Culture. Women in the U.S. are under constant pressure to be very thin. This "ideal" is not realistic for most women. But seeing images of flawless, thin females everywhere can make it hard for women to feel good about their bodies. More and more, men are also feeling pressure to have a perfect body.
Families. It is likely that bulimia runs in families. Many people with bulimia have sisters or mothers with bulimia. Parents who think looks are important, diet themselves, or judge their children's bodies are more likely to have a child with bulimia.

Sometimes, people put pressure on themselves, or the pressure might come from teachers, coaches, or parents.
Media images are part of the problem. Women and men in movies are usually very thin, sending the message that only skinny people are beautiful.

Signs and symptoms
When you have bulimia, you regularly engage in episodes of binge eating followed by attempts to prevent weight gain. A binge is considered eating a larger amount of food than most people would eat under similar situations.

Repeatedly eating large amounts of food in a short period of time (less than 2 hours).
Frequently getting rid of the calories you've eaten (purging) by making yourself vomit, fasting, exercising too much, or misusing laxatives, diuretics, ipecac syrup, or enemas. Misuse of these medicines can lead to serious health problems and even death.

A sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating)

Treatment Of  Bulimia Nervosa

Psychotherapy
Psychotherapy is a general term for a way of treating bulimia by talking about your condition and related issues with a mental health provider. Psychotherapy is also known as therapy, talk therapy, counseling or psychosocial therapy.

Medications
Some medications can be extremely helpful in treatment a person who suffers from bulimia. As always, the medication should be carefully monitored, especially since the patient may be vomiting or taking large amounts of laxatives, which may impact on the medication's use and effectiveness. A trusting and honest relationship must be established between the physician and the individual or mediation compliance will almost certainly become an issue.

Drug Therapy
Drug therapy in the treatment of anorexia nervosa and bulimia nervosa should be used in combination with psychotherapy and nutritional therapy.