Abdominal aortic aneurysms often grow slowly without symptoms, making them difficult to detect. Some aneurysms never rupture. Many start small and stay small; others expand over time, some quickly.

If you have an enlarging abdominal aortic aneurysm, you might notice:

• Deep, constant pain in your abdomen or on the side of your abdomen
• Back pain
• A pulse near your bellybutton

Aneurysms can develop anywhere along the aorta, but most aortic aneurysms occur in the part of your aorta that's in your abdomen. A number of factors can play a role in developing an aortic aneurysm, including:

• Hardening of the arteries (atherosclerosis). Atherosclerosis occurs when fat and other substances build up on the lining of a blood vessel.
• High blood pressure. High blood pressure can damage and weaken the aorta's walls.
• Blood vessel diseases. These are diseases that cause blood vessels to become inflamed.
• Infection in the aorta. Rarely, a bacterial or fungal infection might cause an abdominal aortic aneurysms.
• Trauma. For example, being in a car accident can cause an abdominal aortic aneurysms.

Abdominal aortic aneurysm risk factors include:

• Tobacco use. Smoking is the strongest risk factor. It can weaken the aortic walls, increasing the risk not only of developing an aortic aneurysm, but of rupture. The longer and more you smoke or chew tobacco, the greater the chances of developing an aortic aneurysm.
• Age. These aneurysms occur most often in people age 65 and older.
• Being male. Men develop abdominal aortic aneurysms much more often than women do.
• Being white. People who are white are at higher risk of abdominal aortic aneurysms.
• Family history. Having a family history of abdominal aortic aneurysms increases your risk of having the condition.
• Other aneurysms. Having an aneurysm in another large blood vessel, such as the artery behind the knee or the aorta in the chest, might increase your risk of an abdominal aortic aneurysm.

Tears in one or more of the layers of the wall of the aorta (aortic dissection) or a ruptured aneurysm are the main complications. A rupture can cause life-threatening internal bleeding. In general, the larger the aneurysm and the faster it grows, the greater the risk of rupture.

Signs and symptoms that your aortic aneurysm has ruptured can include:

• Sudden, intense and persistent abdominal or back pain, which can be described as a tearing sensation
• Low blood pressure
• Fast pulse

Aortic aneurysms also put you at risk of developing blood clots in the area. If a blood clot breaks loose from the inside wall of an aneurysm and blocks a blood vessel elsewhere in your body, it can cause pain or block the blood flow to the legs, toes, kidneys or abdominal organs.