An aortic aneurysm is an abnormal bulge that occurs in the wall of the major blood vessel (aorta) that carries blood from your heart to your body. Aortic aneurysms can occur anywhere in your aorta and may be tube-shaped (fusiform) or round (saccular).

Aortic aneurysms include:

• Abdominal aortic aneurysm. An abdominal aortic aneurysm occurs along the part of the aorta that passes through the abdomen.
• Thoracic aortic aneurysm. A thoracic aortic aneurysm occurs along the part of the aorta that passes through the chest cavity.

In some cases, an individual may have an abdominal aortic aneurysm and a thoracic aortic aneurysm.

Having an aortic aneurysm increases your risk of developing an aortic dissection.

An aortic dissection occurs when a tear develops in the inner layer of the wall of the aorta. This causes one or more of the layers of the wall of the aorta to separate, which weakens the wall of the aorta. Having an aortic aneurysm also increases your risk that the aneurysm can burst (rupture).