An aortic aneurysm is a stretched and bulging section in the wall of the aorta, the large artery that carries oxygen-rich blood from the heart to the rest of the body. The weakened and bulging section may burst or rupture, causing life-threatening bleeding.

Aortic aneurysms are most commonly caused by hardening of the arteries (atherosclerosis), but other causes include genetic conditions, infections, and injury.

Most people with aortic aneurysms do not have symptoms. If the aneurysm bursts, there is sudden, severe pain; an extreme drop in blood pressure; and signs of shock.

Surgery is needed for large or fast-growing aneurysms or when symptoms such as pain are present. Smaller aneurysms are usually monitored routinely to see if they get bigger.