An aortic aneurysm occurs when a section of the aorta, the body's main artery, becomes enlarged. The aorta carries blood and nutrients (fuel) from the heart (the engine of the body) to the rest of the body.
Because the aneurysm can stretch and weaken like a balloon, it can burst. If the aorta bursts, it can cause serious internal bleeding that can be fatal.
The aorta looks like a walking cane. The first part is the ascending aorta. The second portion is the arch. The third portion is the descending aorta. Aneurysms can form in any section of the aorta.
When one forms in the belly area—the most common location—it is called an abdominal aortic aneurysm. When one forms in the upper body, it is called a thoracic aortic aneurysm.
The wall of a normal aorta stretches like a balloon. It can expand and contract depending on blood flow. The wall of your aorta can become stiff because of hardening of the arteries (atherosclerosis) often caused by high blood pressure, cholesterol, or age. These conditions also can weaken the aorta wall and cause it to bulge.
Other less common causes of aortic aneurysm include: