What is anorexia nervosa?
Although associated in many people's minds with adolescent girls, anorexia can occur at any age and in both sexes, though ten times as many women are affected as men.The main feature of anorexia nervosa is weight loss. Some people achieve this purely by restricting their food intake, while others use extra means of weight control, such as self-induced vomiting and abuse of laxatives and diuretics (drugs that increase the amount of urine passed). Excessive exercising can also be used. Some people with anorexia also binge eat.

What are bulimia nervosa and binge eating?
Again more women than men suffer from these disorders. People with bulimia can often be of normal weight, but can also be under- or overweight.

Bulimia is characterised by binge eating. Excessive amounts of food are consumed, associated with a sense of loss of control. Bingeing often follows a period of dietary restraint, and this can lead to the establishment of a vicious circle in which bingeing is followed by further efforts at restraint. The bulimic feels intense guilt, which can often only be overcome by vomiting, use of laxatives and starvation. Bulimia is sometimes associated with other impulsive behaviours such as alcohol and drug abuse, repeated self-harm and stealing.

Physical complications
Prolonged and severe weight loss in anorexia nervosa can lead to some or all of the following problems:

Skin and hair: The hair on the head can become thin and fall out, but there can be an increase in body hair, which is of a very fine soft quality, like the hair growing on a developing baby. The skin can be dry and hands and feet cold and blue from poor circulation.

Periods: Once body weight drops below a certain level, periods become infrequent and then stop. Some women have problems becoming pregnant. In teenagers the drop in oestrogen levels caused by severe weight loss can lead to delay in or regression of secondary sexual characteristics.

Heart and blood vessels: The blood pressure can drop due to inadequate body fluid levels, causing episodes of fainting, feeling dizzy and palpitations. Some of these symptoms are secondary to anaemia and a low blood sugar.

Heart muscle can waste away and heart failure can develop. This is one of the commonest ways that anorexics die.

Metabolic: Low blood sugar from inadequate food intake and high cholesterol levels can be found. The liver does not function well. The body temperature drops and the anorexic feels cold all the time because there is so little subcutaneous fat.

Nutrition: The levels of vitamins and minerals can drop, causing low levels of potassium, sodium, magnesium, zinc and calcium. This can lead to abnormal heart rhythms and be very dangerous. Low protein levels can lead to swollen ankles.

Muscles and bones: Muscle weakness and wasting, particularly in the upper arm and leg muscles can occur. Bone protein loss and calcium deficiency can lead to osteoporosis and increased risk of fractures.

Brain power: Concentration is poor and there is difficulty in undertaking complex thought. People with anorexia are frequently depressed, low mood being a common finding in starvation. Epileptic fits can occur with low calcium levels.

Kidneys: Kidney stones can occur and getting up to pass urine at night is common.

Gastro-intestinal system: Emptying of the stomach slows down and constipation is common.