The aorta is the main blood vessel carrying oxygen-rich blood from the heart to various parts of the body. Over time, the aortic walls may lose their elasticity. When this happens, the weakened areas of the aortic wall bulge outward like a balloon. These abnormal bulges are known as aortic aneurysms.
An aneurysm can develop in any part of the aorta. Depending on its location, the aneurysm can be classified as either an abdominal aortic aneurysm, which occurs in the section of the aorta passing through the abdomen or a thoracic abdominal aneurysm, which is caused by a weakening of the upper parts of the aorta.