Anorexia should not be confused with anorexia nervosa.

Anorexia is a general loss of appetite, or a loss of interest in food.
Anorexia nervosa is a serious mental illness. Patients have not “lost” interest in food, they have intentionally restricted their food intake because of an irrational fear of being or becoming fat.
However, lay people often use the term “anorexia” when referring to the serious psychological disorder.

According to the National Library of Medicine1, anorexia nervosa is an eating disorder that makes the patient lose more weight than is considered healthy for his or her height and age.

A person with anorexia disorder may be underweight, but still has an intense fear of putting on weight. They may do too much exercise, diet, use laxatives and other methods to get leaner.

Anorexia nervosa typically begins during a person’s teenage years or early adulthood. It is the third most common chronic illness among teenagers.

ANAD2 (National Association of Anorexia Nervosa and Associated Disorders) says that between 85% to 90% of all patients with anorexia nervosa or bulimia nervosa are female.

Many studies have found that the risk of suicide among patients with anorexia nervosa is high. A study published in PLoS ONE3 found that among eating disorders, anorexia nervosa has the highest rates of completed suicides, but not attempted suicides. However, S. Coren and P. L. Hewitt wrote in the American Journal of Public Health14 that “(our) findings suggest that the suicide rate is not elevated among individuals currently suffering from anorexia nervosa.”

James Lock, MD, PhD, a professor of psychiatry and behavioral sciences at Stanford University Medical School says that anorexia nervosa kills approximately 1 in every 10 patients4 (all causes, not just suicide).

What are the causes of anorexia nervosa?
Anorexia nervosa has no single cause. The National Health Service5, UK, says that the majority of experts believe the mental disorder is caused by a combination of biological, environmental and psychological factors.

Some individuals are thought to have personality traits which make them more susceptible to developing the disease.

Being underweight and not having a normal diet may have an effect on the brain which reinforces behaviors and obsessive thoughts related to anorexia nervosa. In other words, under-eating and being underweight can set off a cycle of further weight loss and under-eating.

The following risk factors have been associated with anorexia nervosa:

Being overly obsessed with rules
Having a tendency towards depression
Being overly worried about one’s weight and shape
Being excessively worried, doubtful and/or scared about the future
Being perfectionist
Having a negative self image
Having eating problems during early childhood or infancy
Having had an anxiety disorder during childhood
Holding specific cultural/social ideas regarding beauty and health
Inhibition – the individual restrains or controls his or her behavior and expression
Environmental factors – may include the hormonal changes that occur during puberty, plus feelings of anxiety, stress and low self-esteem.

Many experts believe that some young females who in Western cultures are exposed to multiple messages through the media that being thin is beautiful, are more susceptible to developing anorexia nervosa. However, research carried out in the University of Granada, Spain, found the incidence of eating disorders was considerably higher among Muslim adolescents than their Christian peers.

Other environmental factors some experts believe may contribute include physical abuse, sexual abuse, issues with family relationships, being bullied, other school stress (e.g. exams), bereavement, and a stressful life event, such as the breakdown of a relationship or becoming unemployed.

Biological factors – according to NEDA6 (National Eating Disorders Association), studies are finding that in some people with eating disorders certain brain chemicals that control digestion, appetite and hunger may be unbalanced. Nobody is sure what the implications of this might be – further studies are underway to find out.

Experts believe susceptibility to eating disorders may be partly driven by a person’s genes. In many cases, anorexia nervosa, bulimia nervosa and other eating disorders have been found to run in families.