Subarachnoid hemorrhage

Last reviewed: 2 May 2023
Last updated: 24 Jan 2023

Summary

Definition

History and exam

Key diagnostic factors

  • headache
  • photophobia
  • loss of consciousness
  • third cranial nerve palsy
More key diagnostic factors

Other diagnostic factors

  • age >50 years
  • female sex
  • black people
  • nausea/vomiting
  • altered mental status
  • meningismus
  • unilateral or bilateral sixth cranial nerve palsies
  • intraocular hemorrhage
  • focal neurologic deficits
Other diagnostic factors

Risk factors

  • hypertension
  • smoking
  • family history
  • autosomal dominant polycystic kidney disease (ADPKD)
  • alcohol use
  • cocaine use
  • Marfan syndrome
  • Ehlers-Danlos syndrome
  • pseudoxanthoma elasticum
  • neurofibromatosis type I
More risk factors

Diagnostic investigations

1st investigations to order

  • CT head
  • CBC
  • clotting profile
  • serum electrolytes
  • troponin I
  • ECG
More 1st investigations to order

Investigations to consider

  • lumbar puncture (LP)
  • digital subtraction angiography (DSA)
  • computed tomography angiography (CTA)
  • magnetic resonance angiography (MRA)
More investigations to consider

Treatment algorithm

ACUTE

all patients

Contributors

Authors

Salah Keyrouz, MD, FAHA

Associate Professor

Neurology and Neurosurgery

Washington University School of Medicine

St. Louis

MO

Disclosures

SK is an author of a reference cited in this topic.

Acknowledgements

Dr Salah Keyrouz would like to gratefully acknowledge Dr Michael N. Diringer, a previous contributor to this topic.

Disclosures

MND is an author of a number of references cited in this topic.

Peer reviewers

Venkatesh Aiyagari, MD

Associate Professor

Department of Neurology and Rehabilitation

University of Illinois at Chicago

Chicago

IL

Disclosures

VA declares that he has no competing interests.

Peter Martin, MA, BM BCh, MD, FRCP

Consultant Neurologist

Addenbrookes Hospital

Cambridge

UK

Disclosures

PM declares that he has no competing interests.

Giovanni Grasso, M.D., PhD

Aggregate Professor of Neurosurgery

Neurosurgical Clinic

Department of Clinical Neuroscience

University of Palermo

Palermo

Italy

Disclosures

GG declares that he has no competing interests.

  • Subarachnoid hemorrhage images
  • Differentials

    • Nonaneurysmal perimesencephalic SAH
    • Arterial dissection
    • Cerebral and cervical arteriovenous malformation (AVM)
    More Differentials
  • Guidelines

    • ACR Appropriateness Criteria®: headache
    • ACR Appropriateness Criteria®: cerebrovascular diseases - aneurysm, vascular malformation, and subarachnoid hemorrhage
    More Guidelines
  • Patient leaflets

    Subarachnoid haemorrhage

    More Patient leaflets
  • Videos

    Diagnostic lumbar puncture in adults: animated demonstration

    Tracheal intubation: animated demonstration

    More videos
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer