What is an aortic aneurysm?

Large aorta: An aortic aneurysm is an aorta which is larger than it should be. This is typically due weakness of the walls of the aorta. This weakness can be secondary to degenerative change, congenital (born with it) abnormalities of the wall of the aorta, or trauma.

Weak wall: The aorta is a living pipe. It has 3 layers, the inner layer or intima, the middle layer or media were some muscle like cells dwell and the adventitia rich in collagen fibers. The process of arteriosclerosis may result in slow death of the media which then gets replaced by collagen scar. The pressure inside the aorta and the wall weakness will result in dilatation of the aorta and it could burst.

The aorta: The aorta is the large, main artery that carries blood from the heart. An aneurysm (a portion that dilates or expands to a larger than normal diameter) can occur anywhere along its length, from where it emerges from the heart in the chest (thoracic aortic aneurysm) to where it travels through the abdomen & splits into the iliac arteries (abdominal aortic aneurysm, or aaa) - or anywhere between.

Follows the aorta: The aorta starts at the heart (in the chest) extends to the neck, comes down the chest, into the abdomen and divides at the level of the belly button. Most aortic aneurysms are located in the abdomen.