What is anorexia nervosa?

Anorexia nervosa, or simply anorexia, is an eating disorder and a serious mental illness. People with anorexia have a distorted body image and a strong fear of gaining weight. People with anorexia tend to severely limit the amount of food that they eat, or exercise excessively to avoid gaining weight. This usually leads to extreme weight loss.

Anorexia most commonly affects young people. Many people with anorexia tend to hide their condition from others, so the first signs of anorexia may be difficult to identify. The main goal in the treatment of anorexia is getting the affected person back to a healthy weight. The treatment usually requires therapy to help people with the condition think more positively about themselves and their weight and to develop a healthier attitude towards food.

Signs and symptoms

Both men and women can be affected by anorexia, although it is more common in women. A person with the condition severely limits the amount and type of food they eat, or may sometimes eat and then make themselves throw up in order to control their weight. Some men with anorexia may use steroids and exercise excessively, in addition to restricting what they eat, to develop a muscular and toned body. These behaviors can lead to a dangerously low body weight and in some cases may be life-threatening.

Warning signs

It is common for a person with anorexia to try and hide their condition from others. Initially the signs of anorexia may seem like normal dieting behavior, but there are several warning signs that may indicate that a person has anorexia. These may be specific physical signs, changes in behavior, or changes in the way a person thinks.

Physical signs

Physical signs of someone with anorexia include:

Behavioral signs

Some behaviors associated with anorexia include:

  • Extreme dieting;
  • Skipping meals;
  • Excessive exercise, and;
  • Strange food habits, such as cutting food into very small pieces, or only eating food that is one color.

Psychological signs

Psychological signs associated with anorexia include:

  • Obsession with food and body shape;
  • Low self-esteem;
  • Having a distorted body image;
  • Depression or anxiety, and;
  • Inability to concentrate.

Anorexia can cause psychological and behavioral changes related to body weight and image. 

Causes and risk factors

It is not known exactly what causes anorexia. It is thought to develop from a combination of genetic and environmental factors. Anorexia is commonly associated with other mental illnesses such as anxiety, depression and obsessive-compulsive disorder.

A person may be more likely to develop anorexia if they:

  • Have a close family member with an eating disorder;
  • Have experienced a traumatic or stressful event, such as bullying or physical abuse, and;
  • Have low self-esteem.

The media places a lot of emphasis on having a thin body type and young people, in particular, may feel as though there is a lot of pressure on them to be thin. It is thought that this is a factor that contributes to the development of eating disorders, such as anorexia.

A teenage girl standing in front of a mirror unhappy with her reflection. 


There are two subtypes of anorexia that are classified on the basis of the methods of controlling their weight.

Restricting anorexia

Most people with anorexia severely restrict the amount of food they eat in order to control their weight.

Binging and purging anorexia

Some people with anorexia will binge eat and then make themselves throw up or misuse laxatives to get rid of the food. This is similar to the binging and purging of another eating disorder called bulimia nervosa, except that people with anorexia tend to be dangerously underweight, while people with bulimia tend to be within the normal weight range.

Methods for diagnosis

There are many different types of eating disorders. To work out if you have anorexia or another eating disorder, a doctor will ask you about your medical history, mental health and lifestyle.

Types of treatment

The main goal of treatment for anorexia is getting back to a healthy weight and helping you to develop healthy attitudes towards food. Treatment will usually involve components that will look after your medical and mental health.


Psychotherapy is sometimes referred to as 'talking therapy' and describes the process of treating a mental illness by helping people to understand their condition and manage their symptoms. Some common types of psychotherapy used to treat anorexia include family-based therapy (FBT) and cognitive behavior therapy (CBT).

Family-based therapy

Family-based therapy is commonly used to help treat children and teenagers with anorexia. It involves getting parents involved in helping their child gain weight through increasing food intake and reducing exercise. This type of therapy is guided by a specially trained healthcare professional and is usually conducted over a 6-12 months.

Cognitive behavior therapy

Cognitive behavior therapy involves meeting regularly with a therapist to discuss your thoughts and feelings to help you manage your condition. This type of therapy can help to teach people affected by an eating disorder healthy ways of thinking about food and how to think more positively about themselves and their weight.

A young woman in a session with a therapist.Psychotherapy or 'talking therapy' can assist with treatment of anorexia nervosa.  


In some cases, a doctor may prescribe medication to treat underlying mental health problems, such as depression or obsessive-compulsive disorder, which can be associated with anorexia. Medication may include antidepressants such as selective serotonin reuptake inhibitors (SSRIs).

Antidepressants generally need to be taken for at least two weeks before there is any improvement in symptoms. When stopping antidepressant medication, the dose usually needs to be reduced gradually over time to prevent any withdrawal responses.

Side effects

As with many medications, some people may experience side effects when taking antidepressants. Some common side effects include nausea, dizziness, tiredness and sexual dysfunction. Some antidepressants can have more serious side effects if they are taken with certain other medications or herbal remedies, or when combined with alcohol.

Very rarely, some antidepressants may increase suicidal thoughts and the risk of suicide. The risk is highest in the first weeks after starting antidepressant treatment, or when the dose of antidepressants is changed. If someone experiences suicidal thoughts, it is important to contact a doctor immediately.


Most cases of anorexia are treated outside of a hospital. However, people with severe symptoms of anorexia may need to be admitted to hospital if they are at high risk of serious medical complications.

Sexual dysfunction

Any abnormal difficulty that interferes with the sexual response or sexual activity of an individual or a couple.

Potential complications

Anorexia is a very dangerous condition that can be life-threatening and lead to serious medical complications. The most serious complication of anorexia is sudden death, which may occur as a result of multiple organ failure from a lack of nutrition. People who have anorexia also tend to have other mental health issues, such as depression and anxiety and have a high risk of suicide.

The lack of proper nutrients from anorexia can result in slow growth or delayed puberty in young people. It can also cause problems with the digestive system, such as bloating or constipation, weak and brittle bones (osteoporosis) and an irregular heartbeat.

Re-feeding syndrome

There are several serious complications that can occur when someone with anorexia is re-fed. This is known as re-feeding syndrome. It occurs because of shifts in fluids and electrolytes in the body when food is reintroduced in someone who is severely malnourished. These shifts can overwhelm the body's metabolism and in severe cases result in death. The risk of re-feeding syndrome developing may be reduced if it is started with a low level of energy replacement.


Substances that form ions when dissolved in water. These include potassium and sodium minerals that are necessary for normal functioning of the body and all its cells.


The sum of all chemical changes that take place within an organism to maintain growth and development and convert food into energy and building blocks.


Anorexia is a long-term condition. While it is possible to recover from anorexia, recovery can be very challenging and may require ongoing treatment for several years. Some people with anorexia will struggle with their weight for the rest of their lives. However, cases in which the warning signs are detected and treated early have a better chance of recovery. A team of doctors, therapists and other healthcare professionals can help people with the condition return to a healthy lifestyle.


There is no known way to prevent anorexia. However, there are several steps that can be taken to reduce the chance of developing an eating disorder, including promoting a positive body image, improving self-esteem and learning about nutrition and good general health.

Support services

If you or someone you know needs help, please call or visit:

Eating Disorders | Mental Health America Call 1-800-273-TALK or Text MHA to 741741

FAQ Frequently asked questions