Anorexia nervosa results from an interaction of several different factors.
Most researchers agree that one of the most important causes of anorexia nervosa is Western society's emphasis on thinness and body shape as a primary measure of attractiveness.
In fact, many believe that most people who develop anorexia are female because there is more pressure for women to be thin.
Media images of very thin models and actors lead many people to believe that they will only be considered attractive and successful if they are also very thin.
These images may cause many people to develop unrealistic expectations for their own bodies.
People may also feel pressure from family members or peers to be thin.
These social pressures interact with a variety of other factors to cause some people to develop anorexia nervosa.
Some people who develop the disorder have experienced physical, sexual, or emotional abuse or the loss of someone close to them, such as a parent.
Other existing psychological problems, such as anxiety, depression, and compulsive behavior, can also contribute to the development of the illness.
In some cases, the characteristics of a person's family may encourage personality traits associated with anorexia nervosa, such as perfectionism, emotional reserve, desire to conform and avoid conflict, and need for control.
The onset of the disorder in the mid- to late teenage years leads some researchers to believe that the disorder sometimes reflects a patient's fear of emerging sexuality.