Bulimia nervosa, or more commonly just bulimia, is a mental illness that is typified by patients who usually force themselves to vomit right after eating. It is far more common in women than men. However, it is very common among certain occupations in males where low weight is important, such as jockeys. Generally, bulimia patients will eat to excess and then vomit afterwards (so called "binge and purge" behavior). They usually feel that they weigh too much, but cannot stop themselves from eating. This perception persists even in patients who are well below the body mass index which is considered dangerous.
Bulimics use a number of techniques to induce vomiting, some of which are more dangerous than others. For example, the use of emetics, usually used by doctors to induce vomiting in poisoning patients, have serious side effects. However, in all patients, the constant vomiting damages the esophagus, the tissues of the mouth, the teeth, and the nasal cavities, all of which are exposed to stomach acid. Malnutrition is also a common problem.
Bulimia, like the other major eating disorder anorexia nervosa, is exceedingly difficult to treat. Patients will often literally starve themselves to death in addition to risking other complications, and never reach a weight where they feel they are thin enough. As such, they usually require the constant care of a psychiatrist as well as support from family in order to stave off bulimic behavior.