The part of the aorta, the largest artery in the body, in the abdomen is called the abdominal aorta. Expansion or ballooning of the abdominal aortic vessel may cause the vessel to rupture. Rupture in the vein causes internal bleeding, which can be life-threatening. Why Are Aortic Aneurysms Dangerous? The aneurysm may rupture suddenly, causing internal bleeding. According to statistics, internal bleeding caused by aneurysm...