An aortic aneurysm is a balloon-like bulge in the aorta, the large artery that carries blood from the heart through the chest and torso.
Aortic aneurysms can dissect or rupture:
The force of blood pumping can split the layers of the artery wall, allowing blood to leak in between them. This process is called a dissection. The aneurysm can burst completely, causing bleeding inside the body. This is called a rupture. Dissections and ruptures are the cause of most deaths from aortic aneurysms.