Risk of subarachnoid haemorrhage in other family members

There is an increased risk of subarachnoid haemorrhage in relatives of a patient with SAH. The risk for first degree relatives is seven times that for second degree relatives. Some authors suggest that screening for unruptured aneurysms be considered in first degree relatives of patients with SAH.

NICE state:

• routine testing to check for aneurysms in relatives has not been shown to save lives or prevent aneurysmal subarachnoid haemorrhages
• testing for relatives is based on an assessment of the relative's own risk
• testing is usually limited to people with at least 2 first-degree relatives (father, mother, sister or brother) who have had an aneurysmal subarachnoid haemorrhage
  
  
• tell people where they can find more information about testing for relatives, such as the NHS webpage on diagnosis of brain aneurysm.

Reference:

1. Bormberg JE et al. Subarachnoid haemorrhage in first and second degree relatives of patients with subarachnoid haemorrhage. BMJ 1995; 311: 288-9.
2. NICE (November 2022).Subarachnoid haemorrhage caused by a ruptured aneurysm: diagnosis and management