Causes

The exact cause of anorexia is unknown. As with many diseases, it's probably a combination of biological, psychological and environmental factors.

• Biological. Although it's not yet clear which genes are involved, there may be genetic changes that make some people at higher risk of developing anorexia. Some people may have a genetic tendency toward perfectionism, sensitivity and perseverance — all traits associated with anorexia.
• Psychological. Some people with anorexia may have obsessive-compulsive personality traits that make it easier to stick to strict diets and forgo food despite being hungry. They may have an extreme drive for perfectionism, which causes them to think they're never thin enough. And they may have high levels of anxiety and engage in restrictive eating to reduce it.
• Environmental. Modern Western culture emphasizes thinness. Success and worth are often equated with being thin. Peer pressure may help fuel the desire to be thin, particularly among young girls.