A person with bulimia nervosa exhibits a preoccupation with food and often secretly binge eats. A binge is an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances (eg, most people will overeat on vacation). Bingers also exhibit a lack of control over eating during the episode, caloric intake ranging from 3,000 to 40,000 per episode. The incidence of this disorder is unknown, as it is secretive and kept hidden out of fear or shame. Bulimia nervosa often begins in adolescence, but reported incidences range from ages 5 to 70.

Binge episodes are followed by various forms of purging. Vomiting can be induced by inserting a finger or other object down the throat. After a while, it may no longer be necessary to induce vomiting. The person will check that everything ingested has been vomited before completing the purge. The immediate aftermath feelings are of relief, of power, of being able to overeat but avoid the consequences, of “winning,” and of fooling everyone. One young woman reported, “It’s the one thing my father can’t control.” These feelings are positively reinforced and help explain why the disorder continues. However, negative feelings such as self-hatred, self-hatred, fear of being found out, guilt, and being out of control follow the positive ones. Boulemics often vow never to do this again.

Other forms of purging include laxatives (typically 2-30 laxatives per use), diuretics, diet pills, or enemas. These methods do not achieve weight loss, but the feeling of getting rid of the intake is still satisfying and empowering. Non-purgative methods include excessive exercise (up to five hours per day), which can be rationalized as fitness. Fasting, an attempt to compensate for excessive eating, is self-defeating in the sense that it triggers binges again when the person feels hungry.

The physical ramifications of binging followed by purging can include swollen salivary glands, ruptured blood vessels in the eyes, a ruptured stomach, esophageal tears, dehydration, electrolyte imbalance (which endangers heart function), and malnutrition. Because vomit erodes the enamel on the inside of teeth, an eight-year-old bulimic reports that dental repairs cost $10,000.

Bulimia nervosa has several causative factors. A biological factor targets serotonin in the brain and its regulation of satiety and food preferences, as well as in the regulation of impulses. Approximately 85% of bulimic patients suffer from hypoglycemia (low blood sugar), which can contribute to the urge to binge; over time, the behavior develops addictive qualities. A multilevel model for the etiology of bulimia nervosa includes social, cultural, familial, and personal factors: society overvalues ​​thinness and obesity is highly stigmatized; bulimic families express increased anger, aggression, and conflict (no conflict resolution skills), indirect communication, lack of support, and lack of economy; overattention to food and weight in the family (the degree of symptoms is associated with the occurrence among mothers and sisters); excessive preoccupation with pleasing others; strong peer group influences to be attractive (thin), gain approval from other women, and attract boyfriends; feeling of ineffectiveness and low interoceptive awareness, generating high anxiety; a disconnection from unpleasant feelings by diverting attention to food. Bulimics may display other impulsive behaviors, such as drinking, sexual promiscuity, kleptomania, excessive spending, and drug use.