• Anorexia
  Anorexia is characterized, most commonly, by a refusal to eat normally. This doesn't mean that the person doesn't eat at all, but his or her eating habits are such that significant weight loss occurs. Anorexia is sometimes accompanied by extreme physical activity, or hair, skin, or nail problems, and often by depression or low self-esteem.
  
• Bulimia
  Bulimia is almost like a combination of compulsive overeating and anorexia. Someone who's bulimic will consume large amounts of food at a time, but compensate for the "binge eating" through a variety a ways, including; self-induced vomiting, excessive exercise, over-use or misuse of diet pills or laxatives, or fasting.
  
• Compulsive overeating (binge eating)
  Most commonly characterized by impulsive, excessive, eating, binge eaters don't try to compensate for their over-eating like someone who's bulimic. Instead, feelings of shame often cause repeated episodes.

The symptoms of these disorders are not universal and the causes of eating disorders are not always what you'd expect.

As mentioned earlier, teenage girls are especially susceptible to developing eating disorders. The adolescent years are tough. Everyone wants to "fit in", be accepted. Unfortunately, society has created unrealistic expectations regarding the ideal female body. Thanks to Hollywood, and the fashion industry, "super-thin" is in. As young women become more aware of their appearance, some may feel pressured to take extreme measures to attain this impossible ideal. What is just as unfortunate is that many young women get noticed when they begin to loose weight, even if they do it in an unhealthy manner. The acknowledgement they receive may motivate them to continue loosing weight.

Eating disorders occur more often when there is instability at home. If parents fight often, are in the midst of a divorce or separation, or if some form of abuse is taking place, a young woman may resort to an eating disorder in an effort to maintain control over some aspect of her life. She may also find comfort in food, especially if parents are too busy, too critical, or simply not present at all.

If you think that someone you know may be struggling with an eating disorder, don't be afraid to ask him or her. Be careful not to accuse, but instead, simply express your concern. Once you've done that, the most important thing you can do is listen. If you're concerned for a middle schoo, high school, or college student, do your best to get the parents or guardians involved. Sit down, if possible, with the entire family, and help them talk through resolutions and possible next steps. There are lots of resources available for teens who struggle with eating disorders, and their friends and family.