Patients with anorexia nervosa (AN) typically have low body weight, intense fear of gaining weight, and a body image disturbance.
While more often detected in women, cases of AN in young men may be under-represented.
Weight restoration with re-feeding techniques is essential for prevention of sequelae, such as heart failure, fertility problems, and osteoporosis.
Patients with AN are often identified through family referral, paediatric monitoring of weight during routine physical examination, and the patient's physical complaints.
Early intervention is key in order to prevent long-term psychiatric and physical complications of AN.
Among psychiatric illnesses, AN has one of the highest premature mortality rates (with a risk of premature death of approximately 5-fold greater than that of peers).
Anorexia nervosa (AN) is an eating disorder characterised by restriction of caloric intake leading to low body weight, an intense fear of gaining weight, and a body image disturbance.
History and exam
Key diagnostic factors
- presence of risk factors
- significantly low body weight
- fear of gaining weight or becoming fat, or behaviours that interfere with weight gain despite evidence of significantly low body weight
- disturbed body image
- calorie restriction
- binge-eating and/or purging
- misuse of laxatives, diuretics, or diet pills
- decreased subcutaneous fat
Other diagnostic factors
- general fatigue, weakness, and poor concentration
- significant preoccupation with thoughts of food
- orthostatic hypotension
- non-specific gastrointestinal symptoms
- cardiac symptoms and signs
- changes to hair, skin, and nails
- dependent oedema
- osteopenia or osteoporosis
- female sex
- adolescence and puberty
- obsessive and perfectionist traits
- exposure to Western media
- genetic influence
- middle and upper socio-economic classes
1st investigations to order
- serum chemistry
- thyroid function tests
- liver function tests
Investigations to consider
- bone densitometry (dual-energy x-ray absorptiometry)
- estradiol in females
- testosterone in males
medically stable and suitable for outpatient treatment
medically unstable or outpatient failure
Evelyn Attia, MD
Professor of Psychiatry
Columbia University and Weill Cornell Medical College
EA receives royalties from UpToDate for authorship.
B. Timothy Walsh, MD
Professor of Psychiatry
BTW has received royalties from Guilford Press, McGraw-Hill, Oxford University Press, the British Medical Journal, Johns Hopkins University Press, and UpToDate for authorship, and from Guidepoint Global for consultation.
Professor Evelyn Attia and Professor B. Timothy Walsh would like to gratefully acknowledge Dr Pauline S. Powers and Dr Abby M. Irwin, previous contributors to this topic.
PSP and AMI declare that they have no competing interests.
Heather Thompson-Brenner, MD
Eating Disorders Program Center for Anxiety and Related Disorders
HTB declares that she has no competing interests.
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Anorexia: questions to ask your doctorMore Patient leaflets
Body Mass Index (BMI) percentiles for boys (2 to 20 years)
Body Mass Index (BMI) percentiles for girls (2 to 20 years)More Calculators
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