When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Cerebral aneurysm

Last reviewed: 28 Oct 2023
Last updated: 14 Jul 2023



History and exam

Key diagnostic factors

  • headache
More key diagnostic factors

Other diagnostic factors

  • seizures
  • nuchal rigidity
  • decreased level of consciousness
  • focal neurologic deficit
Other diagnostic factors

Risk factors

  • smoking
  • moderate- to high-level alcohol consumption
  • family history of subarachnoid hemorrhage
  • previous subarachnoid hemorrhage
  • heritable connective tissue disease
  • hypertension
  • head trauma
  • intracranial infection
  • tumor
  • arteriovenous malformations or fistulas
  • drug abuse
More risk factors

Diagnostic investigations

1st investigations to order

  • CT head scan
  • conventional catheter-based angiogram
  • CT angiography
  • magnetic resonance angiography (MRA)
More 1st investigations to order

Investigations to consider

  • lumbar puncture
More investigations to consider

Treatment algorithm


unruptured aneurysm

ruptured aneurysm



Brendan Eby, MD

Assistant Professor

Departments of Neurology, Neurosurgery, and Radiology

Washington University School of Medicine

St. Louis



BE has been a paid speaker at a national neurointervention fellows course sponsored by Penumbra Inc; the talk was unrelated to the sponsor's products or services.


Dr Eby would like to gratefully acknowledge Dr Grasso and Dr Michael Chen, the previous contributors to this topic.


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

Peer reviewers

David Altschul, MD

Chief of Neurovascular Surgery

Montefiore Medical Center

New York



DA declares that he has no competing interests.

Peter Martin, MA, BM BCh, MD, FRCP

Consultant Neurologist

Addenbrookes Hospital




PM declares that he has no competing interests.

  • Cerebral aneurysm images
  • Differentials

    • Arteriovenous malformation
    • Hypertensive intracerebral hemorrhage
    • Cerebral venous sinus thrombosis
    More Differentials
  • Guidelines

    • Guidelines for the management of patients with aneurysmal subarachnoid hemorrhage
    • Guidelines on management of unruptured intracranial aneurysms
    More Guidelines
  • Patient leaflets

    Emergency treatment for a stroke

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

Use of this content is subject to our disclaimer