Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin.
Individuals with anorexia nervosa have a fear of being overweight or being seen as such, despite the fact that they are typically underweight. The DSM-5 describes this perceptual symptom as "disturbance in the way in which one's body weight or shape is experienced". In research and clinical settings, this symptom is called "body image disturbance" or body dysmorphia. Individuals with anorexia nervosa may also deny that their symptoms or behaviors are indicative of illness. They may weigh themselves frequently, eat small amounts, and only eat certain foods. Some patients with anorexia nervosa binge eat and purge to influence their weight or shape. Purging can manifest as induced vomiting, excessive exercise, and/or laxative abuse. Medical complications may include osteoporosis, infertility, and heart damage, along with the cessation of menstrual periods. Complications in men may include lowered testosterone. In cases where the patients with anorexia nervosa continually refuse significant dietary intake and weight restoration interventions, a psychiatrist can declare the patient to lack capacity to make decisions. Then, these patients' medical proxies decide that the patient needs to be fed by restraint via nasogastric tube.