Anorexia nervosa: what it is, signs, symptoms and treatment

The NHS describes anorexia as an eating disorder in which people try to keep their weight as low as possible by eating too little, exercising excessively, taking laxatives or vomiting. Starvation can make them very ill. Many have a distorted body image, believing they are fat when they are underweight.

The eating disorder charity Beat describes two main subtypes. In the restricting subtype, food intake and the types of food are severely limited. In the binge-purge subtype, restriction is combined with behaviours such as excessive exercise, vomiting, laxative misuse, or cycles of bingeing and purging. It can be confused with bulimia nervosa, but people with the binge-purge subtype continue to restrict overall and are typically underweight.

Beat stresses that you cannot tell how unwell someone is by looking at them or by weight alone. People may check their body or weigh themselves constantly, or avoid scales and mirrors, and may have a deep fear of gaining weight. Where a person has the same symptoms without being underweight, the diagnosis may be atypical anorexia, classed as a type of other specified feeding or eating disorder.

• Missing meals or eating very little, and thinking about food a great deal.

• Avoiding foods seen as fattening and following strict food rules.

• Believing you are fat when a healthy weight or underweight.

• Periods stopping, or not starting in younger girls.

• Physical problems such as dizziness, lightheadedness, hair loss and dry skin.

• Making yourself sick, exercising excessively, or using appetite suppressants, laxatives or diuretics.

• In under-18s, weight and height lower than the minimum expected for age; in adults, an unusually low BMI.

The NHS says you can recover from anorexia, but it may take time, and your treatment plan should be tailored to you and consider any other support you might need, such as for depression or anxiety. Adults should be offered a type of talking therapy to help manage feelings about food and eating so that they are able to eat enough to be healthy. Under-18s should be offered family therapy and may also be offered another talking therapy, such as CBT or adolescent-focused psychotherapy.

NICE guideline NG69 sets out the structure of each programme.

The NHS advises seeing a GP as soon as you can if you think you may have anorexia. The GP asks about eating habits and feelings, probably weighs you and checks heart rate, blood pressure and temperature, and may arrange blood tests. If an eating disorder is suspected they should refer you to an eating disorder specialist or team. Bringing a friend or loved one to the appointment can make it easier.

If you are worried about someone else, the NHS suggests telling them you are concerned, encouraging them to see a GP, and offering to go with them.

The NHS lists complications of long-term malnutrition: problems with muscles and bones including tiredness, weakness and osteoporosis, and problems with physical development in children and young adults; fertility problems and loss of sex drive; heart and circulation problems including an irregular heartbeat, low blood pressure, heart valve disease, heart failure and swollen ankles; difficulties with concentration and memory, or less often seizures; kidney or bowel problems; and a weakened immune system or anaemia.

The NHS says these usually begin to get better once food intake starts improving, and Beat says that with early intervention many physical effects can improve or be reversed. Beat also notes that the effects of starvation can lead to loss of muscle strength and reduced bone strength, and that periods may stop.

Anorexia can also put life at risk. The NHS says it is one of the leading causes of deaths related to mental health problems, and that deaths may be due to physical complications or suicide.

NICE says people whose physical health is severely compromised should be admitted to a medical inpatient or day patient service for stabilisation and refeeding, if this cannot be done as an outpatient. It says not to rely on a single weight or BMI threshold, and to consider the rate of weight loss and signs such as a very slow heart rate or abnormal heart tracing. Decisions are made case by case.

Beat says anorexia in children and young people is similar to that in adults in terms of its psychological characteristics, but children might, in addition to being of low weight, also be smaller in stature than others their age and slower to develop physically. The NHS says that in under-18s a weight and height lower than the minimum expected for their age is a sign.

NICE says anorexia-focused family therapy (FT-AN) for children and young people should typically consist of 18 to 20 sessions over 1 year, emphasise the role of the family in helping the person recover, and not blame the person or their family. Children and young people may also be offered CBT for eating disorders.

The NHS says the exact cause is unknown. You may be more likely to develop an eating disorder if you or a family member has a history of eating disorders, depression, or alcohol or drug addiction; if you have been criticised about eating, shape or weight; if you are overly concerned with being slim, particularly with pressure from society or a job such as ballet, modelling, athletics or jockeying; if you have anxiety, low self-esteem, an obsessive personality or perfectionism; or if you have experienced abuse.

The NHS suggests letting them know you are worried, encouraging them to see a GP, and offering to go with them. Beat says it is not always obvious that someone has an eating disorder, because they are mental illnesses, and that behaviour changes are often noticeable before changes to physical appearance. Beat says to seek help as quickly as possible if you are at all worried, even if only some signs are present.

NICE says family members or carers may feel guilty and responsible for the eating disorder, and that families should be supported rather than blamed.

NHS eating disorder services are accessed through a GP referral, and Beat provides information on going to the doctor and finding local support. Private eating disorder clinics also exist, including residential units; ask what treatment approach is used, how medical monitoring is provided and how care would continue when you leave.