An aortic aneurysm (say "a-OR-tik AN-yuh-rih-zum") is a bulge in part of the aorta, your main artery. If the bulge gets large enough, it can rupture. If it does, your life is in danger.
Aortic aneurysms are usually caused by hardening of the arteries (atherosclerosis). But other causes include genetic conditions, infections, and injury.
Aneurysms need to be repaired if they are large or fast-growing or if they cause symptoms. Smaller ones are usually just checked regularly to see if they are getting bigger.