Causes
By Mayo Clinic staffMost aortic aneurysms occur in the part of your aorta that's in your abdomen. Although the exact cause of abdominal aortic aneurysms is unknown, a number of factors may play a role, including:
- Tobacco use. Cigarette smoking and other forms of tobacco use appear to increase your risk of aortic aneurysms. In addition to the damaging effects that smoking causes directly to the arteries, smoking contributes to the buildup of fatty plaques in your arteries (atherosclerosis) and high blood pressure. Smoking can also cause your aneurysm to grow faster by further damaging your aorta.
- Hardening of the arteries (atherosclerosis). Atherosclerosis occurs when fat and other substances build up on the lining of a blood vessel, increasing your risk of an aneurysm.
- Infection in the aorta (vasculitis). In rare cases, abdominal aortic aneurysm may be caused by an infection or inflammation that weakens a section of the aortic wall.
Aneurysms can develop anywhere along the aorta, but when they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. More commonly, aneurysms form in the lower part of your aorta and are called abdominal aortic aneurysms. These aneurysms may also be referred to as AAA or triple A.
- Aneurysm. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/arm/printall-index.html. Accessed Feb. 15, 2013.
- Aortic aneurysms. The Society of Thoracic Surgeons. http://www.sts.org/patient-information/aneurysm-surgery/aortic-aneurysms. Accessed Feb. 15, 2013.
- Aortic aneurysms. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/print/cardiovascular_disorders/diseases_of_the_aorta_and_its_branches/aortic_aneurysms.html. Accessed Feb. 16, 2013.
- Screening for abdominal aortic aneurysm. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf/uspsaneu.htm. Accessed Feb. 16, 2013.
- Lewiss RE, et al. Vascular abdominal emergencies. Emergency Medicine Clinics of North America. 2011;29:253.
- Papadakis MA, et al. Current Medical Diagnosis & Treatment 2013. 52nd ed. New York, N.Y.: The McGraw-Hill Companies; 2013. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=1. Accessed Feb. 16, 2013.
- Lederle FA, et al. Long-term comparison of endovascular and open repair of abdominal aortic aneurysm. New England Journal of Medicine. 2012;367:1988.
- U.S. News best hospitals 2012-2013: Top-Ranked Hospitals for Cardiology & Heart Surgery. http://health.usnews.com/best-hospitals/rankings/cardiology-and-heart-surgery. Accessed Feb. 16, 2013.


Find Mayo Clinic on