What Is an Aneurysm?

An aneurysm (AN-u-rism) is an abnormal bulge or “ballooning” in the wall of an artery. Arteries are blood vessels that carry oxygen-rich blood from the heart to other parts of the body. An aneurysm that grows and becomes large enough can burst, causing dangerous, often fatal, bleeding inside the body.

Most aneurysms occur in the aorta. The aorta is the main artery that carries blood from the heart to the rest of the body. The aorta comes out from the left ventricle (VEN-trih-kul) of the heart and travels through the chest and abdomen. An aneurysm that occurs in the aorta in the chest is called a thoracic (tho-RAS-ik) aortic aneurysm. An aneurysm that occurs in the aorta in the abdomen is called an abdominal aortic aneurysm.

Aneurysms also can occur in arteries in the brain, heart, intestine, neck, spleen, back of the knees and thighs, and in other parts of the body. If an aneurysm in the brain bursts, it causes a stroke.

About 15,000 Americans die each year from ruptured aortic aneurysms. Ruptured aortic aneurysm is the 10th leading cause of death in men over age 50 in the United States.

Many cases of ruptured aneurysm can be prevented with early diagnosis and medical treatment. Because aneurysms can develop and become large before causing any symptoms, it is important to look for them in people who are at the highest risk. Experts recommend that men who are 65 to 75 years old and have ever smoked (at least 100 cigarettes in their lifetime) should be checked for abdominal aortic aneurysms.

When found in time, aneurysms can usually be treated successfully with medicines or surgery. If an aortic aneurysm is found, the doctor may prescribe medicine to reduce the heart rate and blood pressure. This can reduce the risk of rupture.

Large aortic aneurysms, if found in time, can often be repaired with surgery to replace the diseased portion of the aorta. The outlook is usually excellent.

August 2006