Anorexia nervosa is an eating disorder characterized by extremely low body weight, distorted body image and an obsessive fear of gaining weight.
The term anorexia is of Greek origin: a (α, prefix of negation), n (ν, link between two vowels) and orexis (ορεξις, appetite), thus meaning a lack of desire to eat.
Anorexia has an incidence of between 8 and 13 cases per 100,000 persons per year and an average prevalence of 0.3% using strict criteria for diagnosis. The condition largely affects young adolescent females, with females between 15 and 19 years old making up 40% of all cases. Furthermore, the majority of cases are unlikely to be in contact with mental health services. Approximately 90% of people with anorexia are female.