What is anorexia nervosa?
Anorexia nervosa is a serious mental health condition. It's an eating disorder where a person keeps their body weight as low as possible.
People with anorexia usually do this by restricting the amount of food they eat, making themselves vomit, and exercising excessively.
The condition often develops out of an anxiety about body shape and weight that originates from a fear of being fat or a desire to be thin. Many people with anorexia have a distorted image of themselves, thinking they're fat when they're not.
Anorexia most commonly affects girls and women, although it has become more common in boys and men in recent years. On average, the condition first develops at around the age of 16 to 17.
Signs and symptoms of anorexia
People with anorexia often go to great lengths to hide their behaviour from family and friends by lying about what they've eaten or pretending to have eaten earlier.
Signs someone may have anorexia or another eating disorder include:
- missing meals, eating very little, or avoiding eating any fatty foods
- obsessively counting calories in food
- leaving the table immediately after eating so they can vomit
- taking appetite suppressants, laxatives , or diuretics (a type of medication that helps remove fluid from the body)
- repeatedly weighing themselves or checking their body in the mirror
- physical problems, such as feeling lightheaded or dizzy , hair loss , or dry skin
People with anorexia often don't seek help, perhaps because they're afraid or don't recognise they have a problem. Many have hidden their condition for a long time – sometimes years.
The most important first step is for someone with anorexia to realise they need help and want to get better.
If you think someone you know has anorexia, try talking to them about your worries and encourage them to seek help.
This can be a very difficult conversation because they may be defensive and refuse to accept they have a problem. However, it's important not to criticise or pressure them as this can make things worse.
You may want to seek advice from an eating disorder support group such as Beat about the best way to raise the subject.
If you think you may have anorexia, try to seek help as soon as possible. You could start by talking to a person you trust, such as a member of your family or a friend, and perhaps ask them to go with you to see your doctor.
Before anorexia can be treated, a physical, psychological and social needs assessment will need to be carried out by a doctor or an eating disorders specialist. This will help them work out a suitable care plan.
In most cases, treatment will involve a combination of psychological therapy and individually tailored advice on eating and nutrition to help gain weight safely.
A range of different healthcare professionals will usually be involved in your care, such as doctor, psychiatrists, specialist nurses and dietitians.
Most people are able to be treated on an outpatient basis, which means you can go home between appointments. More serious cases are treated in hospital or specialist eating disorder clinics.
It can take several years of treatment to fully recover from anorexia, and relapses are common. For example, a woman may relapse if she tries to lose weight gained during pregnancy.
Around half of people with anorexia will continue to have some level of eating problem despite treatment.
If anorexia remains unsuccessfully treated for a long time, a number of other serious problems can develop. These can include fragile bones (osteoporosis), infertility , an irregular heartbeat, and other heart problems.
Despite being an uncommon condition, anorexia is one of the leading causes of mental health-related deaths. This can be because of the effects of malnutrition or as a result of suicide.
Read more about the potential complications of anorexia.
Symptoms of anorexia
The main symptom of anorexia is deliberately losing a lot of weight, although there are often a number of other physical and psychological signs there's a problem.
Intentional weight loss
A person with anorexia will want to weigh as little as possible – much less than is healthy for their age and height. They're so afraid of gaining weight they can't eat normally.
In an attempt to lose weight, they may:
- miss meals, eat very little, or avoid eating any fatty foods
- lie about what and when they've eaten
- obsessively count the calories in food
- lie about how much they weigh
- exercise excessively
- take appetite suppressants, such as slimming or diet pills
- make themselves vomit – you may notice they leave the table immediately after meals or have dental problems such as tooth decay or bad breath caused by the acid in vomit
They may also take laxatives or diuretics, a type of medication that removes fluid from the body, although in reality these have little effect on calories absorbed from food.
Self-esteem, body image and feelings
People with anorexia often believe their value as a person hinges on their weight and how they look. They may think others will like them more or they'll feel happier if they're thinner, and see their excessive weight loss in a positive way.
They often have a distorted view of what they look like, thinking they look fat when they're not.
Some people with anorexia may try to hide how thin they are by wearing loose or baggy clothes.
Many people with the disorder 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
People with anorexia also usually have low self-esteem or self-confidence. They may withdraw from relationships, become distant from family and friends, and lose interest in activities they previously enjoyed.
Anorexia can also affect the person's school work or how well they perform their job.
Other signs of anorexia
Eating too little for a long time can also cause physical symptoms, such as:
- bloating or constipation
- feeling lightheaded or dizzy
- feeling very tired
- feeling cold
- discoloured hands and feet caused by poor circulation
- dry skin
- hair loss from the scalp
- abdominal pain
- problems sleeping
- fine downy hair (lanugo) growing on the body
- brittle nails
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 others of the same age.
Women and older girls with anorexia may stop having their monthly periods, known as amenorrhoea, or absent periods.
Read more about the complications of anorexia nervosa.
Causes of anorexia
The exact causes of anorexia nervosa are unclear, but most specialists believe it's likely to be the result of a combination of factors.
Many people who develop anorexia share certain personality and behavioural traits that may make them more likely to develop the condition. These include:
- a tendency towards depression and anxiety
- finding it difficult to handle stress
- excessive worrying and feeling scared or doubtful about the future
- perfectionism – setting strict, demanding goals or standards
- being very emotionally restrained
- having feelings of obsession and compulsion, but not necessarily obsessive compulsive disorder – unwanted thoughts, images or urges that compel them to perform certain acts
It's also been suggested some people with anorexia have an overwhelming fear (phobia) of being fat.
Puberty seems to be an important environmental factor contributing to anorexia. It may be the combination of hormonal changes and feelings of stress, anxiety and low self-esteem during puberty that triggers anorexia.
Western culture and society may also play a part. Girls – and, to a lesser extent, boys – are exposed to a wide range of media messages that constantly reinforce the idea that being thin is beautiful.
Magazines and newspapers also focus on celebrities' minor physical imperfections, such as gaining a few pounds or having cellulite.
Other environmental factors that may contribute towards anorexia include:
- pressures and stress at school, such as exams or bullying, particularly teasing about body weight or shape
- occupations or hobbies where being thin is seen as the ideal, such as dancing or athletics
- a stressful life event, such as losing a job, the breakdown of a relationship, or bereavement
- difficult family relationships
- physical or sexual abuse
Anorexia often starts off as a form of dieting that gradually gets out of control.
Biological and genetic factors
It's been suggested changes in brain function or hormone levels may also have a role in anorexia, although it's not clear if these lead to anorexia or if they develop later as a result of malnutrition.
These changes may affect the part of the brain that controls appetite, or may lead to feelings of anxiety and guilt when eating that improve when meals are missed or after excessive exercise.
The risk of someone developing anorexia is also thought to be greater in people with a family history of eating disorders , depression, or substance misuse, which suggests genes could play a role.
When trying to determine whether you have an eating disorder, your doctor will probably ask questions about your weight and eating habits.
For example, they may ask:
- if you've lost a lot of weight recently
- how you feel about your weight and whether you're concerned about it
- if you make yourself vomit regularly
- whether your periods have stopped and, if so, for how long
- if you think you have an eating problem
It's important to answer these questions honestly. Your doctor isn't trying to judge you or catch you out – they just need to accurately assess your condition.
Weight and BMI
Your doctor will usually check your weight. The weight of a person with anorexia nervosa is at least 15% below average for their age, sex and height.
Your doctor may also calculate your body mass index (BMI). For adults, a healthy BMI is 18.5 to 24.9, although sometimes doctors may be concerned if a person's BMI is below 20. Adults with anorexia generally have a BMI below 17.5.
BMI isn't designed for use in those under the age of 18. Special charts known as centile charts need to be used for this group.
Your doctor may not need to carry out any tests to diagnose anorexia nervosa, but they may check your pulse and blood pressure, take your temperature, and examine your hands and feet to see whether you have signs of any complications of anorexia .
Your doctor may also ask you to carry out some simple physical exercises, such as moving between sitting, squatting and standing, to assess your muscle strength.
If you have anorexia, you have a higher risk of developing some heart conditions, such as an irregular heartbeat (arrhythmia). Sometimes an electrocardiogram (ECG) may be needed. This is where a number of small, sticky patches (electrodes) are put on your arms, legs and chest to record the electrical signals produced by your heart.
Your doctor may also carry out blood tests to check your general health and the levels of chemicals or minerals such as potassium.
Referral to a specialist
If your doctor thinks you may have anorexia, they may refer you to a specialist in eating disorders for a more detailed assessment and treatment, although they will sometimes carry out this assessment themselves.
Read more about treating anorexia.
The treatment for anorexia nervosa usually involves a combination of psychological therapy and supervised weight gain.
It's important for a person with anorexia to start treatment as early as possible to reduce the risk of serious complications of anorexia , particularly if they've already lost a lot of weight.
The treatment plan
Doctors are often closely involved in ongoing treatment, although other healthcare professionals are usually involved, including:
- specialist counsellors
- specialist nurses
- paediatricians in cases affecting children and teenagers
Before treatment starts, members of this multidisciplinary care team will carry out a detailed physical, psychological and social needs assessment, and will develop a care plan.
Most people with anorexia are treated as an outpatient, which means they visit hospitals, specialist centres or individual members of their care team for appointments, but return home in between.
In more severe cases, a person may need to stay in hospital or a specialist centre for longer periods during the day (day patient), or they may need to be admitted as an inpatient.
A number of different psychological treatments can be used to treat anorexia. Depending on the severity of the condition, treatment will last for at least 6 to 12 months or more.
Cognitive analytic therapy (CAT)
Cognitive analytic therapy (CAT) is based on the theory that mental health conditions such as anorexia are caused by unhealthy patterns of behaviour and thinking developed in the past, usually during childhood.
CAT involves a three-stage process:
- reformulation – looking at past events that may explain why the unhealthy patterns developed
- recognition – helping people see how these patterns are contributing towards the anorexia
- revision – identifying changes that can break these unhealthy patterns
Cognitive behavioural therapy (CBT)
Cognitive behavioural therapy (CBT) is based on the theory that how we think about a situation affects how we act and, in turn, our actions can affect how we think and feel.
In terms of anorexia, the therapist will attempt to show how the condition is often associated with unhealthy and unrealistic thoughts and beliefs about food and diet.
The therapist will encourage the adoption of healthier, more realistic ways of thinking that should lead to more positive behaviour.
Read more about cognitive behavioural therapy.
Interpersonal therapy (IPT)
Interpersonal therapy (IPT) is based on the theory that relationships with other people and the outside world in general have a powerful effect on mental health.
Anorexia may be associated with feelings of low self-esteem, anxiety and self-doubt caused by problems interacting with people.
During IPT, the therapist will explore negative issues associated with your interpersonal relationships and how these issues can be resolved.
Focal psychodynamic therapy (FPT)
Focal psychodynamic therapy (FPT) is based on the theory that mental health conditions may be associated with unresolved conflicts that occurred in the past, usually during childhood.
The therapy encourages people with anorexia to think about how early childhood experiences may have affected them. The aim is to find more successful ways of coping with stressful situations and negative thoughts and emotions.
Anorexia doesn't just impact on one individual – it can have a big impact on the whole family. Family intervention is an important part of treatment for young people with anorexia.
Family intervention should focus on the eating disorder, and involves the family discussing how anorexia has affected them. It can also help the family understand the condition and how they can help.
Gaining weight safely
The care plan will include advice about how to increase the amount eaten so weight is gained safely.
Physical health – as well as weight – is monitored closely. The height of children and young people will also be regularly checked to make sure they're developing as expected.
To begin with, the person will be given small amounts of food to eat, with the amount gradually increasing as their body gets used to dealing with normal amounts.
The eventual aim is to have a regular eating pattern, with three meals a day, possibly with vitamin and mineral supplements.
An outpatient target is an average gain of 0.5kg (1.1lbs) a week. In a specialist unit, the aim will usually be to gain an average of around 0.5-1kg (1.1-2.2lbs) a week.
See treating malnutrition for more information about what gaining weight at home or in hospital may involve.
Occasionally, someone with anorexia may refuse treatment even though they're severely ill and their life is at risk.
In these cases, as a last resort doctors may decide to admit the person to hospital for compulsory treatment under the Mental Health Act. This is sometimes known as sectioning or being sectioned.
Treating additional problems
As well as the main treatments mentioned above, other health problems caused by anorexia will also need to be treated.
If you make yourself vomit regularly, you'll be given dental hygiene advice to help prevent stomach acid damaging the enamel on your teeth.
For example, you may be advised not to brush your teeth soon after vomiting to avoid further abrasion to tooth enamel, and to rinse out your mouth with water instead.
Avoiding acidic foods and mouth washes may be recommended. You'll also be advised to visit a dentist regularly so they can check for any problems.
If you've been taking laxatives or diuretics in an attempt to lose weight, you'll be advised to reduce them gradually so your body can adjust. Stopping them suddenly can cause problems such as nausea and constipation.
Medication alone isn't usually effective in treating anorexia. It's often only used in combination with the measures mentioned above to treat associated psychological problems, such as obsessive compulsive disorder (OCD) or depression .
Two of the main types of medication used to treat people with anorexia are:
- selective serotonin reuptake inhibitors (SSRIs) – a type of antidepressant medication that can help people with co-existing psychological problems such as depression and anxiety
- olanzapine – a medication that can help reduce feelings of anxiety related to issues such as weight and diet in people who haven't responded to other treatments
SSRIs tend to be avoided until a person with anorexia has started to gain weight because the risk of more serious side effects is increased in people who are severely underweight. The drugs are only used cautiously in young people under the age of 18.
Read more about the side effects of SSRIs.
People with anorexia nervosa do not often seek help, probably because they are afraid. Many hide their condition for a long time, sometimes years.
They usually find it difficult to admit they have a problem, or even talk about their symptoms. They will probably disagree they need to gain weight, and may not even realise 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.
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 doctor
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 or be critical of them, as this could make things worse.
You may want to seek advice on how best you can help. For example, your doctor or a support group can provide information on:
- how to help the person recognise they have a problem
- treatments available
- how you can support them during their treatment
You could also offer to help by going with the person to see their doctor. See treating anorexia nervosa for more information.
A leading charity for people with eating disorders is Beat, which has a range of information on the help and support available for people with eating disorders, and their friends and families.
If anorexia nervosa isn't treated, it can lead to a number of serious health problems.
In some cases, the condition can even be fatal.
Other health problems
Long-term anorexia can lead to severe complications and health problems, often as a result of malnutrition . Some complications may improve as the condition is treated, but others can be permanent.
Health problems associated with anorexia include:
- problems with muscles and bones – including weakness, fragile bones (osteoporosis) and problems with physical development in children and young adults
- sexual problems – including absent periods and infertility in women, and loss of sex drive and erectile dysfunction in men
- problems with the heart and blood vessels – including poor circulation, an irregular heartbeat, low blood pressure , heart valve disease, heart failure and swelling in the feet, hands or face (oedema)
- problems with the brain and nerves – including fits (seizures) and difficulties with concentration and memory
- other problems – kidney damage, liver damage, anaemia and low blood sugar (hypoglycaemia)
Some people with anorexia develop another eating disorder called bulimia nervosa . This is where a person binge eats and then immediately makes themselves sick, or uses laxatives to rid their body of the food.
If you have anorexia and are pregnant, you'll need to be closely monitored during pregnancy and after you've given birth.
Anorexia during pregnancy can increase the risk of problems such as:
- giving birth early (premature birth)
- having a baby with a low birth weight
- needing a caesarean section
You're also likely to need extra care and support during pregnancy if you previously had anorexia and recovered from it.