Last reviewed: March 2020
Last updated: December  2017



History and exam

Key diagnostic factors

  • mood disturbances
  • sleep disturbances
  • motor disturbances
  • advanced neurologic deficits

Other diagnostic factors

  • spider angiomata
  • palmar erythema
  • peripheral edema
  • jaundice
  • hepatomegaly
  • ascites
  • hemiplegia

Risk factors

  • cirrhosis
  • hypovolemia
  • GI bleeding
  • hypokalemia
  • metabolic alkalosis
  • hypoxia
  • sedative use
  • hypoglycemia
  • infection
  • hepatic or portal vein thrombosis
  • acute hepatic failure
  • portacaval shunt

Diagnostic investigations

1st investigations to order

  • LFTs
  • serum glucose
  • coagulation profile
  • urine culture
  • blood culture
  • urine toxin screen
  • ultrasonography
  • psychometric tests
  • head CT scan
More 1st investigations to order

Investigations to consider

  • EEG
  • ammonia level
  • lumbar puncture
  • abdominal paracentesis
More investigations to consider

Treatment algorithm


Affiliate Assistant Professor, Pulmonary and Critical Care Medicine

Department of Medicine

Oregon Health and Science University School of Medicine




ES declares that she has no competing interests.

Dr Emily Speelmon would like to gratefully acknowledge Dr Robert Hyzy and Dr Meilan Han, previous contributors to this monograph. MH and RH declare that they have no competing interests.

Peer reviewersVIEW ALL

Assistant Professor of Medicine

Division of Gastroenterology

University of Michigan

Ann Arbor



JAM declares that he has no competing interests.

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