An eating disorder is an illness that causes serious disturbances to your everyday diet, such as eating extremely small amounts of food or severely overeating. A person with an eating disorder may have started out just eating smaller or larger amounts of food, but at some point, the urge to eat less or more spiraled out of control. Its symptoms include dry skin, hypercarotenemia, lanugo body hair, acrocyanosis, atrophy of the breasts, swelling of the parotid and submandibular glands etc. Endocrine abnormalities are common; they include low levels of gonadal hormones, mildly reduced levels of thyroxine (T 4 ) and triiodothyronine (T 3 ), and increased cortisol secretion. Menses usually cease, but cessation of menses is no longer a criterion for diagnosis. Bone mass declines. In severely undernourished patients, virtually every major organ system may be affected. Susceptibility to infections is typically not increased.