What causes an aneurysm?

In some cases, aortic aneurysms can be related to smoking, and in other cases it can be related to a genetic disorder. Learn more from Johns Hopkins Medicine about an aortic aneurysm.

What causes aneurysms?
An aneurysm is a portion of a blood vessel wall that balloons outward. When blood flows through arteries from your heart to the rest of your body, it exerts pressure against the walls of your arteries. (That is what a blood pressure reading measures.) If an artery has a weak spot in its wall, the force of the blood can cause the artery wall to bulge. If an aneurysm in one of the key arteries of your body ruptures, it can lead to sudden death. An aneurysm is especially dangerous if it occurs in the aorta, which carries blood away from your heart; the carotid arteries, which carry blood to the brain; or the abdominal aortic artery, the artery that supplies your lower body with blood.

The causes of aneurysms are not yet fully understood, but some factors are known to increase the likelihood of an aneurysm:
  • A defect in the artery wall that you were born with
  • High blood pressure
  • Atherosclerosis, or narrowing of the arteries from a build-up of a substance called plaque
  • Aging
  • Smoking
  • Genetic factors
  • External trauma from an accident

Aneurysms are caused by a weakening of artery walls. When the force of blood flow pushes against a weakened artery wall, it starts to bulge and form an aneurysm. There are many different genetic conditions, medical conditions, injuries, and lifestyle choices that can increase your risk for developing weakened artery walls.

Continue Learning about Aneurysms


Aneurysms form balloons in weakened arteries of our bodies, potentially causing life-threatening problems such as a stroke. Although aneurysms can form in any weakened artery, they commonly occur in the arteries of the brain and i...

n the aorta, the central artery that extends from your heart through the center of your abdomen and chest. Certain medical conditions, such as high blood pressure, can weaken the arteries, which deliver oxygenated blood from our heart to the rest of our bodies. The pressure of blood traveling through the arteries can lead to this balloon-like bulge. You can have an aneurysm for years without symptoms or problems. Others can have an aneurysm that pops, which can lead to a stroke if bleeding occurs in the brain. Ruptured aneurysms must be treated quickly, usually within minutes, or it can become deadly: about 50% of all ruptured aneurysms are fatal.

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.