Loss of appetite (anorexia) implies that hunger is absent—a person with anorexia has no desire to eat. In contrast, a person with an eating disorder such as anorexia nervosa or bulimia nervosa is hungry but restricts food intake or vomits after eating because of overconcern about weight gain.
A brief period of anorexia usually accompanies almost all sudden (acute) illnesses. Long-lasting (chronic) anorexia usually occurs only in people with a serious underlying disorder such as cancer, AIDS, chronic lung disease, and severe heart, kidney, or liver failure. Disorders that affect the part of the brain where appetite is regulated can cause anorexia as well. Anorexia is common among people who are dying. Some drugs, such as digoxin, fluoxetine, quinidine, and hydralazine, cause anorexia.
Most often, anorexia occurs in a person with a known underlying disorder. Unexplained chronic anorexia is a signal to the doctor that something is wrong. A thorough evaluation of the person’s symptoms and a complete physical examination often suggest a cause and help the doctor decide which tests are needed.
Underlying causes are treated to the extent possible. Steps that can help increase a person’s desire to eat include providing favorite foods, a flexible meal schedule, and, if the person desires, a small amount of an alcoholic beverage served 30 minutes before meals. In certain situations, doctors may use drugs, such as cyproheptadine, low-dose corticosteroids, megestrol, and dronabinol, to help stimulate the appetite.