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An Overview of Brain Aneurysms

Patient information A-Z

Who is the leaflet for? What is its aim?

This leaflet is for patients, their families and carers to provide important information about brain aneurysms. It includes the incidental finding, risk factors, management of the condition, and treatment options for brain aneurysms.

What is a Brain Aneurysm?

A brain aneurysm is a weakness in the wall of a blood vessel (artery) in the brain. A bulge, similar to a blister or bleb, forms at the area of weakness. Most aneurysms remain stable but a small number of them can get bigger. The size of the aneurysm, symptoms and general wellbeing are factors considered when determining treatment for brain aneurysm.

What is Aneurysmal Subarachnoid Hemorrhage?

Aneurysmal Subarachnoid Haemorrhage (SAH) is bleeding into the fluid space surrounding the brain caused by rupture of a brain aneurysm. A brain aneurysm usually ruptures without notice.

Most people with SAH present with a 'thunderclap' headache that is severe and sudden. Other symptoms include neck pain or stiffness, sensitivity to light, vomiting, and reduced consciousness. Some patients experience a seizure or a fit at the time of the haemorrhage. However, these symptoms may vary from one person to another.

What are the Risk Factors for Brain Aneurysm?

There is a no single factor that causes brain aneurysms to form. However, the following factors are considered important:

  • Uncontrolled high blood pressure
  • Smoking
  • Certain genetic conditions

How is a Brain Aneurysm Diagnosed?

Most often, a brain aneurysm is diagnosed after a person has suffered a subarachnoid haemorrhage. Occasionally, it is find when a brain imaging is performed for other reasons.

What is An Incidental Finding?

Some brain aneurysms are incidental findings. This means that a brain aneurysm is found on a scan that was done for unrelated symptoms or reasons.

In most cases, incidental brain aneurysms are discussed in Neurovascular multidisciplinary meetings (MDT). We will then discuss the management with you or your referring doctor.

Do Brain Aneurysms Need Treatment?

Not all brain aneurysms require treatment or radiological surveillance.

Treatment is usually offered to people with subarachnoid haemorrhage when an aneurysm is identified as the cause of the haemorrhage. Treatment options are influenced by age, general condition, location and size of the aneurysm, and the severity of the bleed (if there has been a haemorrhage).

Surgery and endovascular procedures are the ways of treating brain aneurysms. These treatment modalities will be discussed further at the time a decision has been made to offer treatment.

Can I Prevent Brain Aneurysm?

The reasons why some have aneurysms but others don’t are not known. But, we advise management of high blood pressure and cessation of smoking.

If you have high blood pressure, book an appointment with your GP.

Smoking is a strong contributing factor to brain aneurysm formation and subsequent rupture. We strongly advise you to stop smoking or vaping. If you need smoking cessation support, please let us know, and we can refer you to CAMQUIT.

Is there a Follow up Imaging for Brain Aneurysm?

Brain aneurysms that have not ruptured do not always need follow up imaging, especially when previous imaging is of good quality and patients remain free from troubling symptoms.

There is no routine imaging follow-up required for brain aneurysms treated by surgery. However, there are surveillance scans for those treated by endovascular procedures. Your doctor or clinical nurse practitioner (CNP) will discuss this with you.

Can I Drive?

The regulations regarding driving are put in place by the DVLA. Current guidance is that you must not drive and inform the DVLA that you have had a cerebral aneurysm that is untreated. The DVLA may contact your Consultant for information regarding your health condition.

People with treated aneurysms by clipping or endovascular procedure must not drive but need not notify DVLA. Driving may resume following clinical recovery (based on the current DVLA guidelines as of May 2022). We recommend that you should not drive until you have been reviewed at your follow-up outpatient appointment and/or have been told by your clinical team that you can resume driving.


British Heart Foundation.

Foster D, Jersey A. Cerebral Aneurysm.StatPearls June 2022.

Nice Guidelines Draft for Subarachnoid Haemorrhage (February 2021).

Contacts/Further information

Neurovascular Clinical Nurse Practitioner (CNP)

01223 216 189

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Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151