Abnormal enlargement of the largest blood vessel of your body is generally referred as an abdominal aortic aneurysm. Abdominal aortic aneurysm is mainly due to the weakened vessels in your body that expand gradually. The bulging is seen due to the pressure of the blood flowing through the vessels in the weaker regions of the aorta.
An aortic aneurysm is nothing but the abnormal enlargement of the aorta. Aorta is the largest blood vessel in your body that supplies blood to the different parts of your body. The bulging of this aorta generally leads to aneurysm. An aneurysm occurs when a segment of your vessels becomes weakened and expands abnormally.