Brain aneurysm

A brain aneurysm is a swelling in a blood vessel in your brain. If the aneurysm bursts it can cause a bleed on your brain, but this is rare.

Symptoms of a brain aneurysm

Most brain aneurysms are small and do not cause symptoms. They're often found during a test for another condition.

If you have a larger aneurysm, you may get symptoms such as:

• a headache
• pain above or around your eye
• changes in your vision, such as double vision
• dizziness and balance problems
• numbness or weakness on 1 side of your face
• difficulty concentrating and speaking
• problems with your short-term memory

If a brain aneurysm bursts, it can cause a bleed on your brain called a subarachnoid haemorrhage.

The main symptom is a sudden, severe headache that's sometimes described as a "thunderclap headache".

Call 112 if:

You or someone else suddenly get:

• a headache that's extremely painful and does not go away
• weakness in the face – 1 side of the face may droop (fall) and it might be hard to smile
• weakness or numbness in 1 arm or down 1 side of the body – it may not be possible to lift both arms fully and keep them there
• speech problems, such as slurring words, sounding confused, or finding it difficult to speak or find the right words
• blurred vision or loss of sight in 1 or both eyes

Do not drive yourself to A&E.

The person you speak to at 112 will give you advice about what to do.

Treatment for a brain aneurysm

Treatment is not usually needed for small brain aneurysms that are not causing symptoms. This is because they often do not get bigger and have a low risk of bursting.

You may just need regular follow-up scans to check if it’s getting bigger.

Brain aneurysm surgery

If there’s a risk of the aneurysm bursting, or if it’s already burst, surgery will usually be needed.

The 2 main types of surgery are:

• surgical clipping – where a small metal clip is attached to the blood vessel in the brain to stop blood flowing into the aneurysm
• endovascular surgery – where a coil or small piece of wire mesh is put inside the aneurysm to slow the flow of blood into it and help a blood clot to form

If possible, your surgeon will talk to you about the procedure they feel is most suitable for you and discuss any risks involved.

General anaesthetic is used for both surgical clipping and endovascular surgery, so you’ll be asleep and unable to feel any pain or discomfort during the procedure.

Causes of a brain aneurysm

It's not always clear what causes brain aneurysms.

But things that increase your chances of getting a brain aneurysm include:

• smoking
• high blood pressure
• having a close relative who has had a brain aneurysm
• an injury to a blood vessel in your brain
• taking drugs, such as cocaine
• having certain genetic conditions, such as autosomal dominant polycystic kidney disease (ADPKD) or Ehlers-Danlos syndrome

Things you can do to help if you have a brain aneurysm

If you have a brain aneurysm there are some things you can do to reduce the risk of it getting bigger and bursting.