Brain Aneurysm

Overview

A brain aneurysm is a weak, bulging spot on the wall of an artery in the brain. Think of it like a balloon that forms on a blood vessel. If it leaks or bursts, it can cause bleeding in the brain, which is a medical emergency. Many brain aneurysms never burst and cause no symptoms at all.

Brain aneurysms are not rare. Studies suggest about 1 in 50 people have a brain aneurysm, but most are small and never cause symptoms. Ruptures are much less common, affecting about 10 in 100,000 people per year.

Brain aneurysms can happen at any age, but they are more common in adults over 40. Women are slightly more likely to have them than men. People with a family history of brain aneurysms or certain genetic conditions may also be at higher risk.

Symptoms

Common symptoms

• Most unruptured brain aneurysms cause no symptoms at all.
• If symptoms do occur, you might have a localized headache, usually behind or above one eye.
• You may notice a droopy eyelid, double vision, or a dilated (enlarged) pupil.
• Some people feel numbness, weakness, or difficulty speaking on one side of the face.
• Pain or pressure around the face or eye can also be a sign.

Symptoms in children

• Brain aneurysms are rare in children, but symptoms may include a sudden severe headache, vomiting, irritability, or a stiff neck.
• Young children may seem unusually tired, confused, or have seizures, so any sudden change in behavior warrants urgent medical attention.

Symptoms in older adults

• Older adults may experience similar symptoms, but a rupture may be less obvious and could cause confusion, fainting, or balance problems rather than a classic severe headache.
• Sudden weakness or changes in vision should never be ignored in an older person.

Causes

Main causes

• A brain aneurysm forms when the wall of an artery becomes weak and bulges outward under blood pressure.
• This weakness can be present from birth (congenital) or develop over time due to wear and tear on the blood vessel wall.
• Certain medical conditions, like polycystic kidney disease or connective tissue disorders, can increase the chance of developing an aneurysm.

Risk factors

• High blood pressure (hypertension) puts constant stress on blood vessel walls.
• Smoking damages and weakens blood vessel walls.
• Family history of brain aneurysm – you are more likely to have one if a close relative has had one.
• Age – risk increases with age, especially over 40.
• Being female – women are affected more often than men.
• Drug abuse, especially cocaine or heavy alcohol use, can spike blood pressure and increase risk.
• Some inherited conditions like Ehlers-Danlos syndrome or Marfan syndrome.

When to see a doctor

See a doctor urgently if:

• If you have a sudden, severe headache, go to the emergency department immediately or call your local emergency number.
• If you develop any symptoms like double vision, drooping eyelid, numbness, or weakness, seek urgent medical care the same day.
• If you have been told you have a brain aneurysm and you notice any new or worsening symptoms, contact your doctor urgently.

Book a routine appointment if:

• If you have a family history of brain aneurysms or a condition that raises your risk, it is reasonable to talk to your general practitioner about whether screening is appropriate.
• If you have high blood pressure, diabetes, or other vascular risk factors, schedule regular check-ups to manage them.

Diagnosis

A brain aneurysm is usually diagnosed with imaging tests that look at the blood vessels in the brain. If you have symptoms of a rupture, a CT scan is done urgently. If symptoms are milder, your doctor may order an MRI or a special X-ray of the blood vessels.

Tests that may be done

• CT scan (computed tomography) – a series of X-rays that can quickly show bleeding in the brain.
• CTA (CT angiography) – a CT scan with a special dye to see the blood vessels.
• MRI (magnetic resonance imaging) – uses magnets and radio waves to create detailed images of the brain and blood vessels.
• MRA (magnetic resonance angiography) – an MRI that focuses on the arteries.
• Lumbar puncture (spinal tap) – a procedure where a small sample of spinal fluid is taken to check for blood, sometimes needed if a scan is not conclusive.

What to expect at your appointment

If you are diagnosed with an unruptured aneurysm, your specialist team will talk through the size, location, and shape of the aneurysm, and your overall health. They will help you weigh the risks of treatment versus the risks of leaving it alone. You may need regular imaging tests to see if the aneurysm changes over time.

Treatment

Treatment for a brain aneurysm depends on whether it has ruptured, its size and location, and your overall health. The goal is to prevent bleeding or re-bleeding and to reduce pressure on the brain. For many small, unruptured aneurysms, the safest approach is active monitoring rather than immediate treatment.

Self-care at home

• Keep your blood pressure well controlled – take any prescribed medicines as directed by your doctor.
• If you smoke, ask your healthcare team about support to stop – quitting smoking is one of the most important things you can do.
• Avoid heavy exertion or straining, which can raise blood pressure sharply, if you have been advised to do so.
• Follow your doctor's advice on caffeine, alcohol, and over-the-counter medicines – some can affect blood pressure or bleeding risk.
• Get regular follow-up scans as recommended to check that the aneurysm is stable.

Medical treatments

Medical management focuses on controlling risk factors. Your doctor may prescribe blood pressure medicine, and if you smoke, they will strongly recommend a smoking cessation program. Sometimes medicines are used to prevent complications like vasospasm (narrowing of blood vessels after a rupture) – the exact approach depends on your situation and should be discussed with your specialist.

When is surgery considered?

Surgery or endovascular treatment is considered when an aneurysm has ruptured, is large, or is causing symptoms. There are two main approaches: surgical clipping, where a small metal clip is placed at the base of the aneurysm to stop blood flow, and endovascular coiling, where tiny coils are threaded through a catheter into the aneurysm to block it. A newer technique called flow diversion uses a stent-like device to redirect blood flow away from the aneurysm. The choice depends on the aneurysm's size, shape, and location, and your overall health.

Living with this condition

Living with a brain aneurysm can feel stressful, but many people manage it well with regular check-ups and a healthy lifestyle. Try to keep your daily routine as normal as possible, but be aware of warning signs. Always carry a list of your medicines and have a plan for what to do if you develop a sudden headache or other emergency symptoms.

Lifestyle tips

• Quit smoking and avoid secondhand smoke.
• Limit alcohol – avoid binge drinking.
• Manage stress with relaxation techniques, like deep breathing, meditation, or talking to someone you trust.
• Avoid recreational drugs, especially stimulants like cocaine.
• Get enough sleep and try to keep a regular sleep schedule.

Diet and exercise

Eating a balanced diet low in salt, saturated fats, and added sugars can help control blood pressure. Include plenty of fruits, vegetables, whole grains, and lean proteins. Regular physical activity is good for overall health, but ask your doctor which intensity is safe for you. Avoid extreme heavy lifting or straining if your doctor advises caution.

Mental health and emotional wellbeing

It is completely normal to feel anxious or fearful after being diagnosed with a brain aneurysm. You might worry about the future or about having a rupture. These feelings are valid. If anxiety or low mood is affecting your daily life, speak to your healthcare provider – they can offer support, counselling, or treatment. You are not alone.

Prevention

You cannot always prevent a brain aneurysm, but you can reduce the risk of developing one and lower the chance of rupture. The most important steps are to control blood pressure, not smoke, and limit alcohol. Managing any inherited conditions with your doctor is also key.

Screening programmes

Screening your imaging for ‘brain aneurysms’ is not usually recommended for everyone. If you have two or more close relatives who have had a brain aneurysm (for example, a parent, sibling, or child), you may consider screening with an MRI or MRA. Talk to your general practitioner or a specialist to discuss the potential benefits and harms of screening in your case.

Complications

If left untreated

• If an unruptured aneurysm grows, it may press on nerves and cause vision problems, facial pain, or other neurological symptoms.
• The most serious complication is rupture, which causes bleeding into the space around the brain (subarachnoid hemorrhage).
• A rupture can lead to brain damage, stroke, coma, or death if not treated immediately.
• After a rupture, other problems can occur, such as vasospasm (narrowing of blood vessels) which may cause a stroke, or hydrocephalus (a buildup of fluid in the brain).

Long-term outlook

The outlook for a brain aneurysm is much better than it used to be. Many unruptured aneurysms are discovered early and can be monitored safely. Even when a rupture happens, rapid treatment saves many lives, and recovery is possible. With modern medicine, supportive care, and rehabilitation, many people go on to live full lives after treatment. Your outlook depends on your specific situation, so ask your specialist about your own risks and what to expect.

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