An abdominal aortic aneurysm—or AAA—is a blood-filled bulge or ballooning of the abdominal aorta, the artery that carries blood away from the heart to the lower part of the body.
Over time, the bulge (known as an aneurysm) can become weak, and the force of normal blood pressure can cause the aorta to rupture. This can lead to severe pain, massive internal bleeding or even sudden death.
Most patients with a ruptured aneurysm do not survive emergency treatment, making AAA the third leading cause of sudden death in men over 60.1
Here is a diagram that shows the progression of an undiagnosed AAA:2–5
The exact causes of AAA remain unknown. The bulge or ballooning may be caused by a weakness in the wall of the aorta where it has become inflamed. Some doctors believe that this inflammation may be due to clogged arteries, but it may also be related to heredity, injury or diseases.
AAA is known as a silent killer because many people do not experience any symptoms. Often aneurysms grow slowly and go unnoticed. Some aneurysms may never reach the point of bursting, while others may enlarge quickly and rupture without warning. Individuals who do experience symptoms often describe them as: