The exact causes of anorexia nervosa are unknown. However, there are many risk factors — among them, social, genetic, biological, environmental, and psychological — that may contribute to this complex condition.

Sociocultural influences can play a large role in attitudes about weight and negative body perceptions. Because unrealistic thinness is prized in western culture, it has reinforced the notion that thin is the ideal body type for everyone, and therefore fuels a sense of dissatisfaction in young women, in particular, when they are unable to attain a certain weight. Eating disorders stem from not being able to achieve this unrealistic goal. Self-worth and success are also equated with thinness in our culture, which further perpetuates the desire to be thin and increases the chances of developing a serious eating disorder.

Genetics and biology can also contribute to anorexia. Eating disorders tend to run in families. If an immediate family member suffers from anorexia, there is a greater likelihood that someone else in that family may be genetically predisposed to an eating disorder, as well; more specifically, certain chromosomes may increase susceptibility to this disease.

Biological factors that could influence eating disorders include altered biochemistry of the brain, which makes certain individuals more likely to develop an eating disorder. The hypothalamic-pituitary-adrenal axis (HPA) releases neurotransmitters (dopamine, serotonin, and norepinephrine) that regulate stress, mood, and appetite. Research has discovered that serotonin and norephinephrine levels may be decreased in those with anorexia nervosa and other eating disorders, which suggests a connection between HPA functioning and abnormal biochemical make up and the likelihood that an individual will develop an eating disorder.

There are a number of environmental factors that can contribute to developing anorexia. If a person grows up in a family where they were criticized for their looks, or in a controlling atmosphere where thinness is valued over character or other more defining characteristics of a healthy, thriving person, they might develop a distorted sense of self and body image. Peer pressure and bullying can also influence one’s sense of self-esteem, leaving them feeling that they are not good enough. Trauma and abuse can also contribute to anorexia. Additionally, in many cases, those diagnosed with anorexia nervosa are more likely to suffer from anxiety.

There are several psychological characteristics that may make a person vulnerable to developing anorexia. Perfectionism is a driving force for those seeking to control their food intake. The very nature of perfectionism leaves these individuals perpetually unsatisfied in their quest for thinness. Those who develop eating disorders are more inclined to have low self worth and low self esteem. They may also exhibit OCD behaviors regarding food and diet.