Bulimia nervosa is characterized by binge eating and inappropriate compensatory behaviors, such as vomiting, fasting, excessive exercise and the misuse of diuretics, laxatives or enemas. Although the etiology of this disorder is unknown, genetic and neurochemical factors have been implicated. Bulimia nervosa is 10 times more common in females than in males and affects up to 3 percent of young women. The condition usually becomes symptomatic between the ages of 13 and 20 years, and it has a chronic, sometimes episodic course. The long-term outcome has not been clarified. Other psychiatric conditions, including substance abuse, are frequently associated with bulimia nervosa and may compromise its diagnosis and treatment. Serious medical complications of bulimia nervosa are uncommon, but patients may suffer from dental erosion, swollen salivary glands, oral and hand trauma, gastrointestinal irritation and electrolyte imbalances (especially of potassium, calcium, sodium and hydrogen chloride). Treatment strategies are based on medication, psychotherapy or a combination of these modalities.