An aneurysm is an abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel.

A thoracic aortic aneurysm occurs in the part of the body’s largest artery (the aorta) that passes through the chest.

Causes

The most common cause of a thoracic aortic aneurysm is hardening of the arteries (atherosclerosis). This condition is more common in people with high cholesterol, long-term high blood pressure, or who smoke.