An aneurysm is a weakened blood vessel in the brain that collects blood. The bulging, blood-filled pocket can put pressure on parts of the brain, pressing on nearby nerves. This can cause symptoms or cause the blood vessel to rupture (hemorrhage). Early detection and diagnosis can help prevent severe or fatal complications. Many aneurysms go unnoticed for a lifetime and cause no symptoms.

Brain Aneurysm

GN00002_brain aneurysm.jpg
© 2010 Nucleus Medical Media, Inc.


Aneurysms form in areas where the artery wall becomes thin or weak. Thinning artery walls and resulting aneurysms can be caused by a number of factors. Common causes include:

  • Congenital (present at birth) weakness in artery wall
  • High blood pressure]]>
  • Infection
  • ]]>Trauma]]> or injury to the brain
  • Tumor
  • Plaque build-up on artery walls


Risk Factors

These factors increase your chance of developing a brain aneurysm. These risk factors also increase your chance of a rupture. Adults are more likely to develop an aneurysm than children. Females are at slightly higher risk. Tell your doctor if you have any of these risk factors:

  • Old age
  • Genetic diseases (circulatory, connective tissue, or kidney diseases)
  • Family history of aneurysms
  • Smoking
  • Heavy alcohol use
  • Drug abuse
  • High blood pressure
  • Tumors
  • Traumatic head injury
  • Arteriovenous malformations]]>



If you have any of these symptoms, do not assume it is due to a brain aneurysm. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:

  • Pain behind the eye
  • Numbness, sometimes on one side of the face or body
  • Weakness on one side of the body or face
  • Vision changes
  • Drooping eyelid

Most aneurysms do not cause symptoms until they leak or rupture. A leaking or ruptured aneurysm may cause:

  • Headache
  • Nausea
  • Vomiting
  • Stiff neck
  • Loss of consciousness


Your doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include the following:

  • Brain imaging, such as CT scan]]> (x-rays seen on a computer) or ]]>MRI]]> (magnetic waves are used to view images of the body)
  • ]]>Catheter]]> , ]]>MRI]]> , or ]]>CT]]> angiography (dye contrast test to view the arteries and veins)
  • ]]>Spinal fluid analysis]]>



Talk with your doctor about the best treatment plan for you. Other medical conditions; lifestyle factors; as well as the type, size, and location of the aneurysm will direct treatment. For a known aneurysm that is not leaking or ruptured, treatment options include the following:


Your doctor may need to monitor you to see if the aneurysm gets larger or begins to leak.


Medicines are not used to fix an aneurysm. Medicines may be used to help lower blood pressure, treat pain, or stop side effects of the aneurysm, like seizures.

Endovascular Embolization

During this procedure, a catheter is thread up to the aneurysm. Coils or balloons are used to fill the aneurysm and stop circulation, causing it to clot. This may need to be done more than once.


Surgical options include microvascular clipping or occlusion.

  • Microvascular clipping—A neurosurgeon cuts off blood flow to the aneurysm.
  • Microvascular occlusion—A neurosurgeon clamps off the entire artery leading to the aneurysm. Sometimes a bypass procedure (rerouting a new blood vessel) is done too.


In many cases, there is no known way to prevent an aneurysm from forming. To help reduce your chances of getting a brain aneurysm or having it burst, take the following steps:

  • Control high blood pressure
  • Stop smoking]]>
  • Avoid recreational drug use
  • Discuss with your doctor:
    • Benefits and risks of oral contraceptives
    • Whether it is safe to use daily ]]>aspirin]]> or other pain medicines that may thin the blood