Living with an unruptured brain aneurysm

Covers what it means to be diagnosed with a brain aneurysm, the risks involved, and what can patients can do to stay safe.

What does it mean to have an unruptured aneurysm?

Unruptured intracranial aneurysms (UIA) are found in about 3% of adults, and most never cause symptoms. Small aneurysms under 7 mm are the ones most often detected incidentally.

How likely is it to rupture?

For most people the annual risk is low, under 0.25% per year. Based on population figures, only one rupture occurs each year for every 300 to 500 people who have an aneurysm.

How do doctors decide between monitoring and treatment?

Teams weigh aneurysm factors such as size, site, shape and growth, and personal factors such as age, blood pressure, smoking, other illnesses and family history. Tools like PHASES estimate rupture risk and ELAPSS estimates growth risk to support shared decisions.

What does monitoring involve?

If monitoring is chosen, you will be advised to control vascular risk factors and have follow-up scans at 6–12 months, then annually or every two years, tailored to your risk of growth. Some units do not follow very small aneurysms under 4 mm in older adults, where the balance of benefit and risk is against intervention.

What symptoms should I watch for?

Most UIAs are silent. Seek urgent help if you develop a sudden, severe headache that peaks within minutes, or new neurological symptoms such as weakness, speech or vision changes, or seizures.

Can medicines help?

Your team will focus on blood pressure and other cardiovascular risks. Aspirin has been suggested in some studies to reduce aneurysm wall inflammation and the chances of growth or rupture, but this is individualised and should only be taken on specialist advice.

Key takeaways

• Most unruptured aneurysms do not rupture, and many are safely monitored.
• Decisions balance aneurysm features and personal risk factors, often using PHASES and ELAPSS.
• Monitoring includes tight control of risk factors and planned imaging follow-up.
• Seek urgent care for a sudden, worst-ever headache or new neurological symptoms.