Checking for an abdominal aortic aneurysm: Who, when, and why?

Guidelines recommend an ultrasound screening test for men ages 65 to 75 who have ever smoked. But others at high risk might also consider this one-time test.

The body's largest artery, the aorta, curves out of the heart down through the center of the body, where it branches into smaller arteries that send blood to various organs and the legs. Over a lifetime, the bottom section of this vessel — the abdominal aorta — may weaken. A thin, weak spot can balloon outward, forming an abdominal aortic aneurysm, or AAA.

Most of these bulges remain small, grow slowly, and pose no serious danger. But a small number swell to two inches or greater in diameter and may rupture, usually without warning and with potentially fatal consequences. (The vessel is normally less than an inch across.)