Bulimia nervosa usually begins in late adolescence, although it may occur earlier in some cases. Like patients with anorexia nervosa, patients with bulimia nervosa typically have a history of dieting after a modest weight gain. However, in the case of the bulimic, the weight loss associated with dieting is relatively small and the dieting is followed by binge eating and purging. The average binge comprises about 1,500 kcal. Although the weight of the typical bulimic is close to normal, some patients with the disorder are nearly anorectic and others are overweight and even obese.
Many bulimics engage in excessive exercise and exhibit concerns about weight and shape.
However, these concerns are not as extreme as the distortions of body image perceived by the anorectic. Purging usually consists of self-induced vomiting, which becomes easier with time and is often facilitated by the consumption of large amounts of fluid. Other forms of purging include laxative abuse, diuretic abuse, and occasionally the chewing and spitting out of food. Major depression, anxiety disorders, substance abuse, and personality disorders frequently accompany bulimia nervosa. In most cases, the disorder appears to be chronic, with remissions and relapses occurring over many years.