A number of factors can contribute to weakness in an artery wall and increase the risk of a brain aneurysm. Brain aneurysms are more common in adults than in children and more common in women than in men. Some of these risk factors develop over time; others are present at birth.

Risk factors that develop over time

These include:

  • Older age
  • Smoking
  • High blood pressure (hypertension)
  • Hardening of the arteries (arteriosclerosis)
  • Drug abuse, particularly the use of cocaine
  • Head injury
  • Heavy alcohol consumption
  • Certain blood infections
  • Lower estrogen levels after menopause

Risk factors present at birth

These include:

  • Inherited connective tissue disorders, such as Ehlers-Danlos syndrome, that weaken blood vessels
  • Polycystic kidney disease, an inherited disorder that results in fluid-filled sacs in the kidneys and usually increases blood pressure
  • Abnormally narrow aorta (coarctation of the aorta), the large blood vessel that delivers oxygen-rich blood from the heart to the body
  • Cerebral arteriovenous malformation (brain AVM), an abnormal connection between arteries and veins in the brain that interrupts the normal flow of blood between them
  • Family history of brain aneurysm, particularly a first-degree relative, such as a parent,  brother or sister
May. 24, 2011