Anorexia nervosa is a common eating disorder. It affects about 1% to 5% of the population and occurs mostly in women between the age group of 13 and 30 (about 90% to 95% cases). Anorexia nervosa, however, can affect any age group and even males. The symptoms or criteria needed to make a diagnosis of anorexia nervosa are:

1. Extreme fear of gaining weight or becoming fat (even when the person is underweight).
2. Excessive weight loss or refusal to maintain normal weight as per the age and height (15% or more below the normal weight) to the point of starvation.
3. Distorted image of the body weight or shape, obsession with body weight or shape and refusal to admit the seriousness of weight loss.
4. Absence of at least three or more menstrual periods in a row in women.

People with anorexia usually limit their food intake or may eat and throw up. According to a research, about 50% of the people with anorexia nervosa do binge eating and later purge to maintain low weight. In binge eating, the person eats an abnormally large amount of food within a certain amount of time; this is usually associated with a feeling of lack of control over eating. Purging means to remove food from the body by self-induced vomiting, excessive use of laxatives and diuretics or enemas.

Other behaviours observed in anorexics include:

1. Unusual behaviour at meal times such as cutting food into small pieces or moving them around the plate rather than eating.
2. Drastic reduction of intake of food.
3. Avoiding eating and skipping meals.
4. Checking weight repeatedly.
5. Denial of hunger.
6. Extreme eating patterns such as strictly limiting calories and fat even when underweight.
7. Preoccupation with exercising such exercising even when the weather is bad, during illness etc.
8. Going to the bathroom immediately after eating.
9. Refusing to eat with other people.
10. Using medications to urinate (water pills or diuretics), having a bowel movement (enemas and laxatives) or decreased appetite (diet pills).

Some other symptoms of anorexia include:

1. Unhealthy appearing skin (blotchy or yellow skin) that is dry and covered with fine hair.
2. Disturbance of thought (confused or slow thinking) along with poor memory or judgment.
3. Depression or feeling unusually low.
4. Dry mouth.
5. Unusual sensitivity to cold (wearing several layers of clothing to stay warm).
6. Loss of muscle, body fat and bone strength.