When a weak area of the abdominal aorta enlarges beyond 4.5 cm, it is called an abdominal aortic aneurysm (AAA). The pressure from within the aorta can cause bulging of the aorta, much like a balloon. A normal aorta is about 1 inch (2.5 centimeters) in diameter. Aneurysms are a health risk because they can burst or rupture. A ruptured aneurysm can cause life threatening internal hemorrhage, which can lead to shock or even death.

 

Each year, physicians diagnose approximately 200,000 people in the United States with AAA. Of those 200,000, nearly 15,000 may have AAA threatening enough to cause death from its rupture if not treated.