Anorexia nervosa is an eating disorder characterized by attempts to lose weight, to the point of starvation.A person with anorexia nervosa may exhibit a number of signs and symptoms, the type and severity of which may vary and may be present but not readily apparent. An eating disorder causing people to obsess about weight and what they eat. Anorexia is characterised by a distorted body image, with an unwarranted fear of being overweight. Symptoms include trying to maintain a below-normal weight through starvation or too much exercise. Medical treatment may be required to restore normal weight. Talk therapy can help with self-esteem and behavioural changes.The main difference between diagnoses is that anorexia nervosa is a syndrome of self-starvation involving significant weight loss of 15 percent or more of ideal body weight, whereas patients with bulimia nervosa are, by definition, at normal weight or above.