Bulimia nervosa is a mental illness, specifically an eating disorder, which is characterized by alternating episodes of binge eating followed by compensatory behaviors. Patients usually have very low self-esteem and are excessively preoccupied with their weight and body image. Their sense of self-worth is almost solely defined by their appearance and they subscribe to unrealistic ideals of beauty.
In order to cope with this, they lapse into episodes of overindulgence in food. This is known as binge eating. As they binge, they suffer extreme guilt, shame and loss of self-control for having succumbed to the temptation to overeat. However, the urge to eat is uncontrollable. Afterward, they attempt to compensate through starvation, excessive exercise or by purging themselves. Usually, purging involves induced vomiting and the abuse of laxatives, diuretics or drugs for weight loss. Their feelings of disgust and shame will typically lead them into another episode of bingeing. Some may even commit self-harm.
This cycle of bingeing and compensatory behavior is the classic hallmark of bulimia. Patients will also go to great lengths to conceal these behaviors from friends and family. As a result, of the bingeing and purging, the person’s weight typically fluctuates a lot. Those suffering from bulimia may never actually become extremely underweight. In fact, some may even gain weight.