What Is a Brain Aneurysm?

Closeup view of brain aneurysm.Arteries are the blood vessels that lead from the heart to organs such as the brain. A brain aneurysm is a balloon-like bulge in the wall of a brain artery. If this bulge tears and bleeds, nearby cells may be damaged. A brain aneurysm can occur in an artery wall that is weak or has a defect. Aneurysm is often associated with hardening of the arteries. High blood pressure, heredity, smoking, alcohol abuse, cocaine abuse, and a head injury are also risk factors.


In most cases, a brain aneurysm has no symptoms until it bleeds or tears. Symptoms of bleeding or tearing include a combination of:

  • Severe headache, nausea, and vomiting

  • Neck stiffness

  • Brief blackout

  • Confusion or sluggishness

  • Vision or speech problems

  • Paralysis or weakness on one side of the body

  • Clumsiness

  • Jerking movements, such as seizures or convulsions

  • Coma

Prompt treatment can save a life

A brain aneurysm needs to be evaluated immediately and treated if possible. Doing so may save a person's life. Some aneurysmal bleeding can only be treated with supportive medical care. If the aneurysm has bled, treatment may not reverse the resulting brain damage. But in many cases, surgery may help prevent more bleeding, remove trapped blood in and around the brain, or relieve excessive brain pressure. Other forms of therapy, such as endovascular coiling or microvascular clipping, to prevent additional bleeding may be considered.

Note to family and friends

Your loved one’s healthcare team will answer any questions you have. After special tests are done and the cause is known, specialists are called. Treatment will begin right away if the aneurysm has already bled. The person may be too ill to know what’s going on. You may need to decide on the extent of his or her treatment. Choose a few family members to talk to the healthcare team. These family members can share what they learn with others. Doing this will make it simpler to keep everyone informed. Sometimes, the aneurysm leads to devastating brain injury that results in such severe injury that life support is required. Sometimes, even the most intensive treatment is not effective in saving someone's life.