Anorexia nervosa

Anorexia nervosa is an eating disorder. It is most common in teenagers and young adults, although it can occur in children as young as seven or eight years old as well as adults of all ages. Around 90 per cent of young people diagnosed with anorexia nervosa are female, however it also affects males.

Anorexia nervosa is a serious mental health problem which, if untreated, can seriously damage an individual’s health and quality of life. In a minority of cases it can be fatal. However, the majority of young people who develop anorexia nervosa recover with appropriate help and support.

Individuals with anorexia nervosa restrict their intake of food to the extent that they lose a considerable amount of weight and become very thin. In children, growth may be slowed or halted when food intake is insufficient to sustain an increase in height. In young people approaching puberty, physical development may be delayed and in girls whose menstrual periods have started, these may stop. 

These disruptions to normal development can have longer term effects such as compromised final adult height, fertility problems and reduced bone density, making it important that nutrition and weight are restored as soon as possible.

People with anorexia nervosa feel unable to eat normal amounts of food due to a disturbance in the experience of their own body weight and shape. This can mean that when they look in the mirror they may not recognise they are underweight even though they are actually very thin. They can experience an extreme and distressing fear of being or becoming overweight, which contributes to behaviours aimed at losing weight or avoiding weight gain, even though this is not necessary. 

These behaviours can include restricting food intake and exercising to burn off calories. Some people with anorexia nervosa may make themselves sick or take laxatives in the belief that this will mean their body does not absorb anything from food they have eaten. However, these behaviours do not achieve this purpose and are much more likely to damage physical health and cause further complications. In some extreme cases they can lead to serious medical problems which can result in death.

People with anorexia nervosa experience a constant struggle with eating and may become very distressed trying to achieve and maintain a healthy weight. They may feel fat despite what the scales or other people say. 

What causes anorexia nervosa?

There is no known single cause for anorexia nervosa and it is generally understood as being due to a combination of factors. These include the person’s genetic make-up, personality characteristics and biological factors, with possible triggers related to what is happening in the individual’s life and social environment. 

Although there is a lot of interest in the influence of the media and fashion images on young people, which may have an impact on an individual’s eating habits, this alone does not cause anorexia nervosa. It can, however, be part of the social context against which an eating disorder develops.

In general, the development of anorexia nervosa is complex. It can be linked to feelings of low self esteem and a wish to try to cope with things in life that are beginning to feel unmanageable, in individuals with particular personality characteristics and a range of other vulnerability factors. The personal context for the development of anorexia nervosa can vary a lot and might for example range from situations where individuals have experienced severe trauma or difficult family circumstances to feelings of failure related to a sense of not fitting in with friends.

People with anorexia nervosa may see their eating behaviour, their weight and their shape as things they can control in their life. They often set themselves high standards in this and other areas, which they try hard to achieve. The standards they set themselves in relation to food intake and weight are unrealistic and not compatible with healthy development and functioning.

What are the signs and symptoms of anorexia nervosa?

The signs and symptoms of anorexia nervosa include:

  • „„Losing weight. Younger teenagers with anorexia nervosa may not necessarily lose large amounts of weight, but if they are still growing and do not put on weight, they effectively become more underweight.
  • „„Periods stopping or failing to start. „„
  • Eating as little as possible, taking a long time to eat food due to repeated chewing, or eating only low-calorie foods.
  • „„Showing an interest in cooking, food shopping, reading recipe books, feeding others.
  • „„Eating small or normal portions of food but then exercising to burn off the calories.
  • „„Attempting to control weight by trying to get rid of the food, for example by vomiting or using laxatives, which do not achieve this purpose and can be very dangerous.
  • „„Wearing baggy clothes.
  • „„Saying they don’t feel hungry at mealtimes.
  • „„Withdrawing from family and friends, not wanting to go out, particularly to situations involving food.
  • „„Fainting, feeling dizzy or cold
  • „„Complaining of abdominal discomfort, for example, stomach bloating, pains.
  • „„Experiencing constipation due to minimal food/fluid intake.
  • „„Dry skin and thin hair that falls out easily.
  • „„Growth of downy hair on the body (known as ‘lanugo’ hair).
  • „„Feeling tired and having problems sleeping.
  • „„Feelings of depression and mood swings. 
  • „„Losing interest in normal hobbies and activities.

How is anorexia nervosa normally diagnosed?

Identifying that a child or young person has anorexia nervosa can be difficult as often they don’t believe they are unwell or have a problem.

A health care professional will measure weight and height to plot where the child falls in terms of body mass index centiles. This is a way of checking if weight is appropriate for height. They will also ask questions about how the young person feels about him- or herself, in particular in relation to weight and shape but also more generally, as well as about their attitudes to food and eating.

A diagnosis of anorexia nervosa will only be made if the the child has lost significant amount of weight relative to their healthy weight, and they have changed their eating behaviour to avoid certain types of foods driven by a fear of fatness.

Sometimes it is necessary to rule out other causes of weight loss, such as diabetes, thyroid problems or some other medical cause before a diagnosis of anorexia nervosa can be confirmed.

How is anorexia nervosa treated?

With anorexia nervosa, it is important to help the child seek help as early as possible. This is because anorexia can cause serious health problems without treatment, and the earlier the treatment starts the more likely it is to work. If they do not get help, girls with anorexia may stop having periods and delay puberty. This can lead to problems having a baby later in life. It can also affect growth and bones, making them break more easily. This can result in osteoporosis even as a teenager.

Treatment for anorexia nervosa is often hard work for all concerned, but varies from case to case. The first step is to recognize that the young person has a problem and seek appropriate help and support. As it can be difficult for a young person to recognize they have a problem, it may be that other people become concerned first. This could be parents, teachers, friends, brothers or sisters or other relatives. Talking about the situation with the young person is important in the early stages of helping them to agree to seek help.

Usually the family doctor will refer the young person to a service that specialises in anorexia nervosa. This may be a local child and adolescent mental health service or a more specialist eating disorder service. Staff in these services will help parents to encourage the child to start eating more adequate amounts and will provide input to help the young person. A dietitian may advise regarding meal planning. Family work has been shown to be helpful in the majority of cases and is likely to be offered. Sometimes individual therapy may be offered to your child as well.

What happens next?

Treatment can take a long time and can be difficult but most people do get back to a normal weight and make a full recovery. It is not true that people with anorexia nervosa can never really fully recover. There are many people who had anorexia nervosa when they were younger, who lead perfectly normal lives and no longer have problems with eating that affect them day to day.

Last review date: 
December 2014