Causes of Aneurysm.shtml" target="_blank" title="Abdominal Aortic Aneurysm">Abdominal Aortic Aneurysm
The most common cause of aortic aneurysms is "hardening of the arteries" called arteriosclerosis. A majority of aortic aneurysms are caused by arteriosclerosis. The arteriosclerosis can weaken the aortic wall and the increased pressure of the blood being pumped through the aorta causes weakness of the inner layer of the aortic wall.

The aortic wall has three layers, the tunica adventitia, tunica media, and tunica intima. The layers add strength to the aorta as well as elasticity to tolerate changes in blood pressure. Chronically increased blood pressure causes the media layer to break down and leads to the continuous, slow dilation of the aorta.

Smoking is a major cause of aortic aneurysm. Studies have shown that the rate of aortic aneurysm has fallen at the same rate as population smoking rates.