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.
Read more about the causes 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:
Read more about the symptoms of anorexia.
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 GP.
Before anorexia can be treated, a physical, psychological and social needs assessment will need to be carried out by a GP 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 GPs, 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.
Read more about the potential complications of anorexia.