Last reviewed: 20 Sep 2020
Last updated: 10 Oct 2018



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
  • amenorrhoea
  • 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

Risk factors

  • female sex
  • adolescence and puberty
  • obsessive and perfectionist traits
  • exposure to Western media
  • genetic influence
  • middle and upper socio-economic classes

Diagnostic investigations

1st investigations to order

  • FBC
  • serum chemistry
  • thyroid function tests
  • liver function tests
  • urinalysis
More 1st investigations to order

Investigations to consider

  • ECG
  • bone densitometry (dual-energy x-ray absorptiometry)
  • estradiol in females
  • testosterone in males
More investigations to consider

Treatment algorithm


Professor of Psychiatry

Columbia University and Weill Cornell Medical College

New York



EA receives research support from the National Institute for Mental Health (NIMH), research support from Eli Lilly & Co (medication only; no support since 2016), and royalties from UpToDate.

Professor of Pediatric Pharmacology

Department of Psychiatry

Columbia University

New York



BTW has received royalties from Guilford Press, McGraw-Hill, and UpToDate for authorship.

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.

Peer reviewersVIEW ALL


Eating Disorders Program Center for Anxiety and Related Disorders

Psychology Department

Boston University




HTB declares that she has no competing interests.

Use of this content is subject to our disclaimer