What increases my risk for a brain aneurysm?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

A brain aneurysm is caused when an artery wall weakens and then balloons or swells. They can occur in anyone at any time, but there are risks that factor into the weakening of artery walls placing some people at higher risk for the aneurysm to rupture. These include:

  • head trauma
  • high blood pressure
  • alcohol abuse
  • drug abuse (particularly of cocaine)
  • hardening of the arteries or other vascular diseases
  • congenital abnormality in the artery
  • some genetic diseases like polycystic kidney disease
  • some circulatory diseases that impact blood flow to the brain
  • cigarette smoking
  • infection
  • older age
  • family history of brain aneurysms, particularly when the family member is a parent or sibling
  • decreased estrogen levels after menopause
  • unusually narrow aorta that constrict the flow of oxygen through the body
  • irregular connections between veins and arteries that interrupt blood flow

Cerebral aneurysms are caused by excessive wear and tear on the inner lining of the blood vessel. Major risk factors for the development of aneurysms are high blood pressure, smoking, estrogen deficiency, and a condition called coarctation of the aorta, in which there is a narrowing in a part of the major blood vessel, the aorta. Genetics also are thought to play a role.

Anyone can develop a brain aneurysm (also called a cerebral aneurysm) at any time. About 1 in 40 people will develop a brain aneurysm, usually between the ages of 40 and 60.

Sometimes a brain aneurysm is caused by conditions that you cannot control, such as:

  • Family history: If two or more close relatives (parents, brothers or sisters, or children) have aneurysms, you may be at risk for a "familial aneurysm." This type of aneurysm tends to rupture while it is still small.
  • Birth defect: You may have been born with a defect in one of your blood vessels that allows an aneurysm to develop.
  • Gender: Women are more likely than men to develop a brain aneurysm.
  • Race: African Americans are more susceptible to brain aneurysm
  • Disease, infection, circulatory disorder: Some genetic diseases and some types of infections and circulatory disorders may cause a brain aneurysm. Aneurysms that occur after an infection in the heart or blood vessels are called mycotic aneurysms.
  • Trauma: An accident with trauma to the head may cause a traumatic aneurysm, a rare type of aneurysm in an artery in the brain.

If you have any of these risk factors, you should talk with your doctor about your family and personal medical history, and ask about early detection screening.

Brain aneurysms can occur in anyone, at any age. They are more common in adults than in children and slightly more common in women than in men. People with certain inherited disorders are at a higher risk.

All cerebral aneurysms have the potential to rupture and cause bleeding within the brain. The incidence of reported ruptured aneurysm is about ten in every 100,000 persons per year (about 27,000 individuals per year in the U.S.), most commonly in people between 30 and 60 years of age. Possible risk factors for rupture include hypertension, alcohol abuse, drug abuse (particularly cocaine), and smoking. In addition, the condition and size of the aneurysm affects the risk of rupture.

This answer from the National Institute of Neurological Disorders and Stroke has been reviewed and/or edited by Dr. William D. Knopf.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.