What is brain aneurysm?

Brain Aneurysm

Brain aneurysm

A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. In some cases, a brain aneurysm may cause no symptoms and go unnoticed. In other cases, the brain aneurysm ruptures. This releases blood into the skull and causes a stroke.

When a brain aneurysm ruptures, the result is called a subarachnoid hemorrhage. Depending on the severity of the hemorrhage, brain damage or death may result.

The most common location for brain aneurysms is in the network of blood vessels at the base of the brain called the circle of Willis.

What are the symptoms of a brain aneurysm?

Most brain aneurysms don't cause symptoms. But in some cases, an aneurysm may press on areas in the brain. This may cause symptoms such as headaches, vision problems, changes in speech, or neck pain. The symptoms depend on what areas of the brain are affected and how big the aneurysm is.

If a brain aneurysm ruptures, symptoms often come on suddenly. They may include:

  • A sudden, severe headache that is different from past headaches.
  • Neck pain.
  • Nausea and vomiting.
  • Sensitivity to light.
  • Fainting or loss of consciousness.
  • Seizures.

How is a brain aneurysm treated?

Procedures to treat aneurysms have risks, and treatment isn't always needed. To decide what's best, you and your doctor will think about things like the aneurysm's size and location, your age, and your medical history.

  • If the aneurysm has a low risk of rupture, you may have regular tests to check it.
  • If the aneurysm is large or causing symptoms or if you've had a ruptured aneurysm in the past, your doctor may recommend treatment. An aneurysm that has bled needs to be treated right away.

Treatments include:

A catheter procedure.

Tools such as tiny coils may be used to stop blood flow to the aneurysm.

A surgery called clipping.

Placing a clip around the base of the aneurysm stops blood flow.

It's important to take steps to reduce your risk of rupture. This includes managing high blood pressure and not smoking.

How is a brain aneurysm diagnosed?

Because unruptured brain aneurysms often do not cause any symptoms, many are discovered in people who are being treated for a different condition.

If your doctor believes that you have a brain aneurysm, you may have the following tests:

Computed tomography (CT) scan.

A CT scan can help identify bleeding in the brain. Sometimes a lumbar puncture may be used if your doctor suspects that you have a ruptured cerebral aneurysm with a subarachnoid hemorrhage.

Computed tomography angiogram (CTA) scan.

CTA is a more precise method of evaluating blood vessels than a standard CT scan. CTA uses a combination of CT scanning, special computer techniques, and contrast material (dye) injected into the blood to produce images of blood vessels.

Magnetic resonance angiography (MRA).

Similar to a CTA, MRA uses a magnetic field and pulses of radio wave energy to provide pictures of blood vessels inside the body. As with CTA and cerebral angiography, a dye is often used during MRA to make blood vessels show up more clearly.

Cerebral angiogram.

During this X-ray test, a catheter is inserted through a blood vessel in the groin or arm and moved up through the vessel into the brain. A dye is then injected into the cerebral artery. As with the above tests, the dye allows any problems in the artery, including aneurysms, to be seen on the X-ray.

How can you care for yourself when you have a brain aneurysm?

Keep your blood vessels as healthy as possible. This may include taking medicine to manage blood pressure. A heart-healthy lifestyle can also help. This includes eating heart-healthy foods. Be active. Stay at a weight that's healthy for you. Try to get enough sleep. And if you smoke or vape, try to quit.

What is a brain aneurysm?

A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. Most brain aneurysms don't cause problems.

Sometimes an aneurysm bursts, or ruptures. Blood may spill into the area between the brain and the skull (subarachnoid hemorrhage). This bleeding in the brain is also called a hemorrhagic stroke. The bleeding may lead to brain damage or even death.

What causes a brain aneurysm?

Brain aneurysms seem to run in some families. They may also form because of hardening of the arteries (atherosclerosis) and aging.

Some things can increase your risk for an aneurysm. They may also increase the risk that an aneurysm will rupture. These include:

Family history.

You may be more likely to have a brain aneurysm if someone else in your family had one. Aneurysms may also be linked to certain inherited diseases.

Previous aneurysm.

If you had one brain aneurysm, you're more likely to have another.

Being a woman.

Women have a higher risk of brain aneurysms than men do.

High blood pressure.

High blood pressure damages artery walls and makes an aneurysm more likely to rupture.


Tobacco use damages arteries and increases the risk that an aneurysm will rupture.

Drugs or heavy alcohol use.

Drugs, such as cocaine, or drinking a lot of alcohol raises the risk of an aneurysm.

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