Anorexia Nervosa – A Guide

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Anorexia nervosa is an eating disorder and a serious mental health condition. Sufferers are anxious about their weight and keep it very low.

Symptoms of anorexia
Causes of anorexia
Getting help for anorexia
Diagnosing anorexia
Treating anorexia
Complications of anorexia


People with anorexia have problems with eating. They are very anxious about their weight and keep it as low as possible by strictly controlling and limiting what they eat. Many people with anorexia will also exercise excessively to lose weight.

It is thought that people with anorexia are so concerned about their weight because they:

  • think they are fat or overweight
  • have a strong fear of being fat
  • want to be thin

Even when a person with anorexia becomes extremely underweight, they still feel compelled to lose more weight.

Though people with anorexia avoid eating food whenever they can, they also develop an obsession with eating and diet. For example, they may obsessively count the calories in different types of foods even though they have no intention of eating it.

Some people with anorexia will also binge eat, i.e. they eat a lot of food in a short space of time. They then try to get rid of the food from their body by vomiting or using laxatives (medication that causes the bowels to empty; normally used for the treatment of constipation.)

The symptoms of anorexia usually begin gradually, such as adopting a restrictive diet. They then often spiral out of control quickly.

How common is anorexia?

Despite being an uncommon condition, anorexia is the leading cause of mental health-related deaths.

Most cases of anorexia develop in girls and women. One in every 200 women is affected. Symptoms of anorexia usually first develop during the teenage years, at the average age of 15 (seeAnorexia – symptoms for more information). But the condition can develop at any time, including childhood.

Anorexia also affects 1 in every 2,000 men. Some experts are concerned that the number of men with the condition may be increasing.

The cause of anorexia is unknown, but most experts believe the condition results from a combination of biological, psychological and environmental factors (seeAnorexia – causes for more information).

The long-term malnutrition associated with anorexia can cause a range of serious complications, such as:

  • osteoporosis (weakening of the bones)
  • kidney disease
  • heart failure


One of the biggest challenges in treating anorexia is that it is a condition characterised by self-denial. Many people with anorexia refuse to admit, or are unable to grasp, that there is anything wrong with them or their behaviour.

If the person is persuaded to seek help, it usually takes five to six years of treatment before they make a complete recovery, and relapses are common.

Treatment for anorexia usually involves talking therapies, such as cognitive behavioural therapy, which aim to change the person’s attitudes and behaviour. Nutritional support is also offered to help them gain weight safely.

Around 20-30% of people with anorexia do not respond to treatment, and around 5% will die from complications caused by malnutrition.

Symptoms of anorexia

The main symptom of anorexia is losing a lot of weight deliberately. For example, by:

  • eating as little as possible
  • making yourself vomit
  • doing too much exercise

A person with anorexia will want their weight to be as low as possible – much less than the average for their age and height. They are so afraid of gaining weight that they cannot eat normally.

After they have eaten, they may try to get rid of food from their body by making themselves sick regularly. Signs of regular vomiting could include:

  • leaving the table immediately after meals
  • dental problems such as tooth decay or bad breath, caused by the acid in vomit damaging their teeth and mouth
  • hard skin on their knuckles, caused by putting their fingers down their throat

The need to obsessively burn calories usually draws people with anorexia to ‘high-impact’ activities, such as running, dancing or aerobics. Some people will use any available opportunity to burn calories, such as preferring to stand rather than sit.

They may try to make food pass through their body as quickly as possible. For example, by taking:

  • laxatives (medication that helps to empty the bowel) or
  • diuretics (medication that helps remove fluid from the body)

In reality, laxatives and diuretics have little effect on the calories absorbed from food.

Eating and food

Although anorexia means ‘loss of appetite’, people with anorexia nervosa do not usually lose their appetite; they like food and feel hungry.

However, they do not think about food in the same way as other people. This can show itself in various ways. For example, they may:

  • tell lies about eating or what they have eaten
  • give excuses about why they are not eating
  • pretend they have eaten earlier
  • tell lies about how much weight they have lost
  • find it difficult to think about anything other than food
  • spend lots of time reading cookery books and recipes

Someone with anorexia nervosa strictly controls what they eat. For example, by:

  • strict dieting
  • counting the calories in food excessively
  • avoiding food they think is fattening
  • eating only low-calorie food
  • missing meals (fasting)
  • avoiding eating with other people
  • hiding food
  • cutting food into tiny pieces – to make it less obvious that they have eaten very little, and to make the food easier to swallow
  • taking appetite suppressants, such as slimming pills or diet pills

They may also drink lots of fluids that contain caffeine, such as coffee, tea and low-calorie fizzy drinks, as these can provide a low-calorie, short-term burst of energy.

Some people with anorexia also begin to use illegal stimulant drugs known to cause weight loss, such as cocaine or amphetamines.

Self-esteem, body image and feelings

People with anorexia often believe that their value as a person is related to their weight and how they look. They think other people will like them more if they are thinner, seeing their weight loss in a positive way.

They often have a distorted view of what they look like (their body image). For example, they think they look fat when they are not. They may try to hide how thin they are by wearing loose or baggy clothes.

Many people will also practise a type of behaviour known as ‘body-checking’, which involves persistently and repeatedly:

  • weighing themselves
  • measuring themselves, such as their waist size
  • checking their body in the mirror

Anorexic people usually have low self-esteem or self-confidence. They may withdraw from relationships and become distant from members of their family and friends.

Anorexia can also affect the person’s school work or how well they perform their job.

They may find it difficult to concentrate, and they might lose interest in their usual activities. They may have few interests, even though they seem busier than usual.

Other signs of anorexia

Eating too little for a long time can result in physical symptoms, such as:

  • fine downy hair (lanugo) growing on their body
  • more hair on their face
  • their pubic hair becoming sparse and thin

Their heartbeat may be slow or irregular, which can lead to poor circulation. They may also:

  • have pain in their abdomen (tummy)
  • feel bloated or constipated
  • have swelling in their feet, hands or face (known as oedema)
  • feel very tired (fatigue), as their sleep patterns may have changed
  • have low blood pressure (hypotension)
  • feel cold or have a low body temperature (hypothermia)
  • feel light-headed or dizzy

In children with anorexia, puberty and the associated growth spurt may be delayed. They may gain less weight than expected (if any) and may be smaller than other people of the same age.

Women and older girls with anorexia may stop having their periods (known as amenorrhoea or absent periods). Anorexia can also lead to infertility.

Causes of anorexia

There is no single cause for anorexia. Most experts have argued that the condition is caused by a combination of psychological, environmental and biological factors, which lead to a destructive cycle of behaviour.

A widely accepted model based on these factors is that some people have distinct personality traits that make them more vulnerable to anorexia.

Environmental factors, such as going through puberty or living in a culture where thinness is an ideal, then causes the person to begin a pattern of long-term dieting and weight loss.

The lack of a normal diet has a biological effect on the brain, which helps reinforce the obsessive thinking and behaviour associated with anorexia.

A cycle then begins. The more the person diets, the greater its effect on the brain and the greater the desire to lose weight. This means that symptoms gradually, and then rapidly, getworse.

Each of these factors is explained in more detail below.

Psychological factors

Research has found that most people who develop anorexia share certain psychological factors that help to define their personality and, to some extent, their behaviour. These include:

  • a tendency towards depression and anxiety
  • poor reaction to stress
  • excessive worrying and feeling scared or doubtful about the future
  • perfectionism –setting strict, demanding goals or standards
  • inhibition – where a person restrains or controls their behaviour and expression
  • feelings of obsession and compulsion (though not necessary ‘full-blown’ obsessive compulsive disorder) – an obsession is an unwanted thought, image or urge that repeatedly enters a person’s mind. A compulsion is a repetitive behaviour or mental act that a person feels compelled to perform.

Environmental factors

The fact that most cases of anorexia develop during puberty suggests that puberty itself is an important environmental factor contributing to anorexia.

It may be that the combination of the hormonal changes during puberty and feelings of stress, anxiety and low self-esteem that many teenagers have during puberty could trigger anorexia.

Another important environmental factor is Western culture and society. Girls (and, to a lesser extent, boys) are exposed to a wide range of different media which constantly reinforce the message that being thin is the only way to be beautiful, and that thinness should be pursued at all costs.

At the same time, magazines and newspapers focus on celebrities’ minor physical imperfections, such as gaining a few pounds or having cellulite.

Other environmental factors that may contribute towards anorexia include:

  • a stressful life event, such as losing a job or a relationship
  • bereavement
  • pressures and stress at school, such as exams or bullying
  • difficult family relationships
  • physical or sexual abuse

Biological factors

Your brain requires a healthy, nutritious diet to function normally. It uses a fifth of all the calories you eat. So the extreme dieting associated with anorexia can disrupt the normal functions of the brain, possibly making anorexia symptoms worse.

Malnutrition can also change the balance of hormones in the body, which can disrupt the normal functioning of the brain.

There are a number of theories on how the brain may be affected by anorexia. One theory is that the changes mentioned above cause the brain to become very sensitive to the effects of an amino acid called tryptophan, found in almost all types of food.

This sensitivity may then cause feelings of anxiety in people with anorexia when they eat. At the same time, starving themselves and excessive exercise is known to lower levels of tryptophan, which may make the person feel calmer and more relaxed.

Another theory is that the system controlling a person’s sense of appetite becomes disrupted.

Appetite is controlled by a part of the brain called the hypothalamus. When your body needs more food, your hypothalamus releases chemicals, known as neurotransmitters and neuropeptides, which stimulate your appetite.

Once you have eaten enough food, your body will release a hormone called leptin, which signals to your hypothalamus that you have eaten enough food. Your hypothalamus will release a different set of chemicals that essentially reward you for eating, and make you feel satisfied.

It is thought that due to changes in the brain, the ‘appetite-reward pathway’ becomes scrambled in people with anorexia. The feeling of fullness after a meal does not produce a sense of reward, but a sense of anxiety, guilt or self-loathing. In turn, feeling hungry may help to reduce these negative feelings.

Getting help for anorexia

Recognising the need for help

People with anorexia nervosa often do not seek help, probably because they are afraid. Many hide their condition for a long time, sometimes years.

They usually find it difficult to admit there is a problem, or even talk about their symptoms. They will probably disagree that they need to gain weight, and they may not evenrealise that anything is wrong.

If someone has anorexia, the most important step towards diagnosis and treatment is for them to:

  • recognise they need help
  • want to get better

However, to take this first step they may need lots of support and encouragement.

Helping yourself

If you have eating problems or think you may have anorexia, it is important to seek help as soon as possible. You could start by:

  • talking to someone you trust, such as one of your family or friends
  • asking them to go with you to see your GP

Helping someone else

If someone close to you is showing signs of anorexia, you may want to offer help and support.

You could try talking to the person about how they feel and encourage them to think about getting help. But try not to put pressure on them and be critical of them, as this could make things worse.

You may want to seek advice on how best you can help. For example, a healthcare professional such as your own GP or a support group can provide information on:

  • how to help the person recognise that they have a problem
  • the treatments available
  • how you can support them during their treatment

You could also offer to help by going with the person to see their GP. See Anorexia nervosa – treatment for more information.

A leading charity for people with eating disorders is ‘beat’, which has a range of information on the help and supportavailable for people with eating disorders, and their friends and families

Diagnosing anorexia

When making a diagnosis, your GP will probably ask questions about your weight and eating habits. For example, they may ask:

  • if you have lost a lot of weight recently or quite quickly
  • how you feel about your weight, and if you are concerned about it
  • if you think you are overweight even though other people think you are thin
  • if you make yourself vomit regularly
  • (in women and girls) whether your periods have stopped, and if so, for how long

It is important to answer these questions honestly. Your GP is not trying to judge you or ‘catch you out’. They just need to accurately assess how serious your symptoms are.

Weight and BMI

Your GP may check your weight. If someone has anorexia nervosa, their weight is generally at least 15% below average for their age, sex and height.

Your GP may also calculate your body mass index (BMI). A normal BMI for adults is 20-25. People with anorexia generally have a BMI below 17.5.

Blood tests and other tests

Your GP may not need to carry out any tests to diagnose anorexia nervosa, but they will probably check your pulse and blood pressure.

If you have anorexia, you have a higher risk of developing some heart conditions, such as irregular heartbeat (arrhythmia). Sometimes an ECG (electrocardiogram) may be needed to check how well your heart is working.

Your GP may do blood tests to check the level of:

  • fluids in your blood
  • chemicals or minerals, such as potassium in your blood (seeAnorexia – complications for more information).

However, blood tests can sometimes give normal results in an anorexic person who is very thin and has a very low body weight.

Referral to a specialist

If your GP thinks you may have anorexia, they may refer you to a specialist in eating disorders for a more detailed assessment – see Anorexia – treatmentfor more information. Your GP sometimes carries out this assessment.

Treating anorexia

Assessing your health

Before your treatment begins, you will probably have an overall assessment of your health. This may be done by your GP or another healthcare professional, such as one that specialises in eating disorders.

The assessment will help your healthcare professional draw up a plan for your treatment and care. For example, they may assess:

  • your health and medical needs
  • your social needs, such as support from family and friends
  • any risks that affect you, such as whether you are at risk of harming yourself
  • how mild or severe your condition is, in case any urgent action is needed

Your care team

If you are diagnosed with anorexia nervosa, your GP will probably be involved in your ongoing treatment and care. Other healthcare professionals may also be involved in your treatment, such as:

  • a specialist counsellor
  • a psychiatrist (doctor who specialises in treating mental health conditions)
  • a psychologist
  • a nurse
  • a dietician (specialist in nutrition)

If a child or teenager has anorexia, a paediatrician (doctor who specialises in children) may also be involved in their treatment.

Your treatment plan

Where you are treated may depend on how mild or severe your condition is. For example, you may be treated:

  • as an outpatient (this is most common)
  • as a day patient or in a day unit
  • as in inpatient in hospital, if your weight loss or symptoms are severe

In some parts of England, eating disorders such as anorexia are treated by community mental health teams, which aremade up of different health and social care professionals.

In other areas, there are units that specialise in treating eating disorders. Some services that treat eating disorders also specialise in treating young people.

Treatment for anorexia usually includes:

  • psychological treatment – talking to a therapist or counsellor
  • advice on eating and nutrition to help you gain weight safely

These treatments work better when combined, rather than on their own.

Your physical health will be monitored closely during your treatment. For example:

  • your weight will be checked regularly
  • you may have regular health checks with your GP or another healthcare professional

In children and young people with anorexia, their growth, development and weight will be monitored closely. Their height will also be checked regularly against the average for their age and sex.

Other health problems caused by your anorexia will also be treated. For example:

  • If you vomit regularly, you will be encouraged to stop. You will be given advice on dental hygiene to help prevent stomach acid damaging the enamel on your teeth. You will also be advised to visit a dentist regularly.
  • If you take laxatives or diuretics, you will be advised to reduce them gradually so thatyour body can adjust. Stopping them suddenly can cause problems, such as nausea and constipation.

Gaining weight safely

Your healthcare professional will give you advice on how to increase the amount you eat so you can gain weight safely.

They will probably ask about your current eating habits and how much fluid you drink, as well as lifestyle issues, such as smoking and alcohol. This will determine what advice they give you, and help them to identify any deficiencies in your diet, such as a lack of vitamins.

Your healthcare professional will help you to develop healthy eating habits, such as:

  • eating more food
  • eating more healthily
  • increasing the nutrients and calories you get from food

You may need to start by eating small amounts of food, then gradually increase what you eat. Your body will not be used to dealing with normal amounts.

You may need to take supplements, such as multivitamins or multiminerals, to adjust the chemical balance in your body. Some experts think that this should be done before you start gaining weight.

Work towards having a regular pattern of eating, with three meals a day. A target weight may be set, so you can aim for a minimum healthy weight.

If you are treated as an outpatient, aim to gain an average of 0.5kg a week. Most people can achieve this by eating around 3,500 to 7,000 extra calories each week. This level of weight gain helps to avoid complications that can occur if you gain weight more quickly, such as a chemical imbalance in your body.

If your weight loss is severe, treatment in hospital may be needed to help you start to gain weight. This is sometimes called ‘refeeding’. Your health will be closely monitored, particularly in the first few days. People treated as inpatients should aim to gain an average of around 0.5–1.0kg (1-2lbs) a week.

Types of psychological treatment

Various types of psychological treatment can be used to treat anorexia, such as:

  • cognitive analytic therapy (CAT)
  • cognitive behavioural therapy (CBT)
  • interpersonal therapy (IPT)
  • focal psychodynamic therapy (FPT)
  • family therapy

These different types of psychological treatments are discussed below.

Cognitive analytic therapy (CAT)

CAT is based on the theory that serious mental health conditions such as anorexia are caused by unhealthy patterns of behaviour and thinking, which a person has developed in their past, usually in their childhood.

CAT involves a three-stage process that you will work through with your therapist:

  • reformulation – you look for events in your past that may explain why the unhealthy patterns developed. For example, you may have feltin control by not eating during a time in your life that was particularly chaotic or stressful
  • recognition – you admit and recognise how these patterns are contributing towards your anorexia
  • revision – after discussion with your therapist, you identify changes you can make to break these unhealthy patterns

Cognitive behavioural therapy (CBT)

CBT is based on the theory that how we think about a situation affects how we act. In turn, our actions can affect how we think and feel. It is therefore necessary to change the act of thinking (cognition) and our behaviour at the same time.

The therapist will show you how the symptoms of anorexia are often associated with unhealthy and unrealistic thoughts and beliefs regarding food and diet. For example, thinking that:

  • ‘putting on weight is the single worst thing that can happen in my life’
  • ‘everyone I know secretly thinks I am fat’
  • ‘if I finish the whole meal then the people I am eating with will think I am greedy and worthless’

The therapist willencourage you to adopt healthier, more realistic ways of thinking that should lead to more positive behaviour.

Interpersonal therapy (IPT)

IPT is based on the theory that our relationships with other people and the outside world in general have a powerful effect on our mental health.

Anorexia may be associated with feelings of low self-esteem, anxiety and self-doubt that are caused by problems with interacting with people.

During IPT, the therapist will explore any negative issues associated with your interpersonal relationships and how these issues can be resolved.

Focal psychodynamic therapy (FPT)

FPT is based on the theory that mental health conditions may be associated with unresolved conflicts that occurred in the past, usually in childhood, that are being re-acted in adult life.

FPT encourages you to think about how early childhood experiences may have affected you. You may then be able to find more successful ways of coping with stressful situations and negative thoughts and emotions.

Family therapy

Anorexia does not just impact on one individual; it can have a big impact on the person’s family.

Family therapy involves the person with anorexia and close members of their family discussing how anorexia has affected the family, and the positive changes the person and their family can make.

Choosing a psychological treatment

With the exception of family therapy, there is little scientific evidence to show that the treatments listed above are effective in treating anorexia.

This is not to say they are ineffective; just that very little research has been done to investigate their effectiveness in anorexia.

Little research has been done in this area because many people with anorexia are in denial about their condition, so are unlikely to take part in medical trials. Also, many medical trials that were done had to be abandoned because many of the participants dropped out.

The type of treatment you choose may be based on personal preference and what services are available in your local area. Some people find using a combination of different treatments useful, such as family therapy and CBT.


Research studies have shown that medication alone is not usually effective in reducing anorexia symptoms.

Medication is usually only recommended to treat any associated symptoms, such as obsessive compulsive disorder (OCD) or depression.

Any medication that is prescribed for you, such as antidepressants, will be recommended in combination with one of the psychological or nutritional treatments described above.

Research has found that a medication called olanzapine may be useful in treating anorexia in people who do not respond to other treatments. Olanzapine was originally designed to treat psychosis (where you are unable to distinguish between reality and imagination), and some researchers have argued that it may also be helpful in reducing a person’s anxiety around issues such as weight and diet.

Side effects of olanzapine include:

  • sleepiness
  • dizziness
  • muscle stiffness or spasms
  • constipation
  • dry mouth
  • rash

Compulsory treatment

Occasionally, someone with anorexia may refuse treatment even though they are severely ill and their life is at risk.

In such a situation, doctors may decide to admit the person to hospital for compulsory treatment under the Mental Health Act. This is sometimes called ‘sectioning’ or being ‘sectioned’.

Complications of anorexia

If anorexia nervosa is not treated, the condition can lead to severe health problems.

If treatment is not improving your symptoms, or you start to get worse, your healthcare professional may consider changing your treatment. This may include treatment in hospital if your health is seriously at risk.

It is quite common for anorexia to return after treatment. For example:

  • if someone’s weight starts to fall again, or
  • after having a baby, when a woman tries to lose the weight she gained during pregnancy

Other health problems

If someone has anorexia for a long time, it can lead to severe complications and health problems that can sometimes be permanent, such as damaged bones.

People with anorexia have an increased risk of:

  • poor circulation and cardiovascular problems
  • heart conditions, such as coronary heart disease and irregular heartbeat (arrhythmia)

Sometimes, anorexia can lead to another eating disorder called bulimia nervosa, where the person binge eats, then immediately makes themselves sick or uses laxatives to rid their body of the food.

Anorexia can cause an imbalance of minerals in the blood, such as potassium, calcium and sodium. These minerals play an important part in keeping you healthy. For example, a common complication is a low level of potassium (hypokalaemia), which can cause:

  • tiredness
  • weakness
  • dehydration
  • kidney damage
  • fits
  • irregular heartbeat (arrhythmia)

Low levels of calcium can cause muscles to contract tightly and painfully (spasms). Lack of calcium and vitamin D can cause bone damage.

Lack of sodium (hyponatraemia) can cause people to become confused. In severe cases, it can cause fits (when your body jerks uncontrollably because of your muscles contracting).

Other complications of anorexia can include:

  • low blood pressure(hypotension)
  • anaemia
  • dental problems, such as tooth decaycaused by regular vomiting (stomach acid affects the enamel on the teeth)
  • low blood sugar levels(hypoglycaemia)
  • acute kidney (renal) failure
  • liver damage
  • heart failure
  • osteoporosis(fragile bones) and loss of muscle strength, particularly in women and girls
  • loss of sex drive (libido) and impotencyin men

Misuse of laxatives can permanently damage the bowels and cause permanent constipation.

Anorexia and pregnancy

If you have anorexia and are pregnant, your GP or midwife will monitor your health closely during your pregnancy and after your baby is born. You may need extra health checks as part of your antenatal and postnatal care.

Anorexia during pregnancy can increase the risk of complications, such as

  • miscarriage
  • giving birth early (premature birth)
  • a low-birthweight baby
  • needing a Caesarean section

You are also likely to need extra care and support during pregnancy if you have previously had anorexia and recovered from it.

Anorexia and other health conditions

If you have anorexia and another health condition, you will need to take extra care of your health. For example:

  • If you have diabetes, you will need regular health checks to help avoid problems with your eyes or other serious complications. This is particularly important if you have type 1 diabetes.
  • If you have a bone condition, such as osteoporosis, your GP will probably advise you to avoid any physical activities that may lead to falls.