Eating disorders are more frequent in women and girls, but they also occur in males.

There are several types of eating disorders, including:

Anorexia: Severe food restriction and excessive weight loss.  Typically, patients with anorexia also engage in vomiting, excessive exercising, and/or misusing laxatives, diuretics or enemas to lose weight.  Individuals with anorexia have a distorted perception of their size and shape, and view themselves as overweight even when they are emaciated. Patients with anorexia may also develop thinning of the bones, brittle hair and nails, dry and yellowish skin, growth of fine hair over body, anemia, muscle weakness, severe constipation, low blood pressure, slowed breathing and pulse, drop in internal body temperature, lethargy, heart problems, or kidney failure.

Bulimia: Recurrent and frequent episodes of binging (eating large amounts of food) and an associated sense of loss of control, shame, and guilt. Compensatory behavior, such as purging (e.g., vomiting, excessive use of laxatives or diuretics), fasting and/or excessive exercise follows a binge. Patients with bulimia are often a normal weight (or slightly overweight), yet they are extremely dissatisfied and preoccupied with their size and shape. Patients with bulimia may also develop electrolyte imbalances, gastrointestinal problems, an inflamed and sore throat, swollen neck glands, sensitive and decaying teeth, kidney problems, and severe dehydration.

Binge Eating Disorder: Recurrent and frequent episodes of binging an associated sense of loss of control, shame, and guilt resulting from the binge. No associated compensatory behavior. People with binge-eating disorder are often overweight or obese. Patients with binge eating disorder may also develop cardiovascular disease, diabetes, and hypertension

Causes
There is no single factor that causes eating disorders. One or several of the following factors may increase the likelihood that someone develops disordered eating: 
Personality: Individuals with eating disorders often have characteristic personality traits such as a lack of emotional stability, obsessiveness, and perfectionism. These traits lead to a tendency to be anxious, depressed, and self-critical.
Coping Skills Deficits: In some individuals, disordered eating provides comfort, numbness, attention, stress release, structure, self-punishment, or avoidance as a way to compensate for the lack of more coping methods. Disordered eating can be triggered by stressful transitions (e.g., going to college), family conflict, academic pressure, and/or significant trauma.
Family Structure: Individuals with disordered eating often have over-involved (enmeshed) families. Patterns of alcohol and drug use, domestic violence, divorce, sexual or physical abuse, or neglect in the family are also common.
Culture: Western culture (society and the media) embraces the notion that thinness is the ideal standard of beauty and attractiveness. Participating in particular sports (e.g., gymnastics, dancing, wrestling) can also lead to a pressure to be thin.
  
Treatment
Because eating disorders have multiple causes, multifaceted treatment approaches with the following components are more likely to be successful: 
Nutritional rehabilitation: Dietitians can help patients set realistic and healthy eating and exercise goals, plan meals, and recognize hunger cues.
Individual and Group therapy: Mental health professionals can help patients identify unhealthy thoughts, triggers, and substitute healthy behaviors in a one-on-one or group setting.
Family therapy: Mental health professionals can help families who are contributing to the disorder or coping with caring for an individual with an eating disorder.