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Abdominal aortic aneurysm

Medically reviewed by Last updated on Jul 27, 2023.

What are abdominal aortic aneurysms?

Harvard Health Publishing

An abdominal aortic aneurysm is an abnormal swelling in the aorta. Smaller aneurysms rarely cause a problem. But over time, they can enlarge, which increases the risk of rupture. This can be fatal.

The aorta is the body's largest artery. It carries oxygen-rich blood from the heart to smaller arteries in the body.

An abdominal aneurysm occurs in the abdominal aorta. This is the part of the aorta between the bottom of the chest and the pelvis.

Abdominal aortic aneurysm

An abdominal aortic aneurysm usually causes a balloon-like swelling. The wall of the aorta bulges out.

Normally, the aorta is about one inch (2.5 centimeters) in diameter. The size increases very gradually as people age. If the abdominal aorta becomes larger than 3 centimeters, this is called an abdominal aortic aneurysm.

Most aortic aneurysms are related to atherosclerosis. In atherosclerosis, fatty deposits build up along the inside walls of blood vessels.

Symptoms of abdominal aortic aneurysms

Most aortic aneurysms don't cause any symptoms. They often are discovered during routine physical exams. Or they are found on X-rays for unrelated illnesses.

When symptoms develop, they can include:

Rarely, floating blood clots form near the aneurysm. These clots can break away. They can block blood vessels elsewhere in the body.

Sometimes an undiscovered abdominal aneurysm ruptures without warning. The patient collapses and dies from massive bleeding inside the abdomen.

Diagnosing abdominal aortic aneurysms

Your doctor will ask about your family history of heart disease. He or she will want to know about any sudden and, perhaps, unexplained, deaths in the family.

Your doctor will ask if you smoke. The doctor will check for high cholesterol, high blood pressure and diabetes.

Your doctor may suspect an aortic aneurysm based on the physical examination. Your doctor may hear abnormal blood flow in your abdomen. Or, your doctor may see and feel a pulsating mass in your abdomen.

In most people an abdominal aortic aneurysm is found on an imaging study for an unrelated illness. Aortic aneurysms can be seen on many different imaging studies. These include x-rays and ultrasound.

Ultrasound is a very accurate test for abdominal aortic aneurysm. And it doesn't expose the patient to radiation.

Expected duration of abdominal aortic aneurysms

Once an abdominal aortic aneurysm develops, it is a lifelong condition. Most grow larger with time.

Preventing abdominal aortic aneurysms

You may be able to reduce your risk of an aortic aneurysm. You can do this by controlling your risk factors for atherosclerosis.

If you smoke, quit now

If you have high cholesterol:

If you have high blood pressure:

If you have diabetes:

Also, exercise regularly and maintain an ideal weight.

Men ages 65 to 75 who have ever smoked should have a one-time screening ultrasound.

Treating abdominal aortic aneurysms

Treatment depends mostly on the size of the aneurysm. The larger the aneurysm, the more likely it is to burst (rupture). A ruptured aneurysm that requires emergency surgery has a higher risk of death than a scheduled aneurysm repair.

Surgery is almost always recommended for anyone with an aneurysm that is leaking.  Even with no symptoms, a person with an aneurysm larger than 6.5 centimeters would almost always have emergency surgery to repair the problem. Surgery generally is recommended for people with aneurysms larger than 5.5 centimeters in diameter, unless there is another illness that makes surgery unusually risky.

People with smaller aneurysms should be monitored with periodic imaging tests, usually using ultrasound. The Society for Vascular Surgery recommends the following imaging schedule based on the size of the aortic aneurysm:

Some experts recommend imaging more often -- yearly for abdominal aortic aneurysms that are smaller than 4.5 centimeters and once every 6 months once they reach 4.5 centimeters.

Surgeons have two options to repair abdominal aortic aneurysms.  The traditional method is abdominal surgery. This involves clamping the aorta temporarily, repairing the blood vessel by cutting away the damaged section and replacing the aneurysm with a plastic patch.

The other method is called endovascular surgery.  Small cuts are made in the groin over a branch of the artery that goes to the leg.  A special tube called a stent is threaded through the artery to the site of the aneurysm. The stent protects the wall of the abdominal aorta from the pressure inside the artery and can stop the artery wall from expanding and weakening.

When to call a professional

Contact your doctor if you notice a pulsating mass in your abdomen but otherwise feel well.

If you have abdominal, back or flank pain along with a pulsating mass, this is an emergency. It requires immediate attention.


The outlook for an untreated abdominal aortic aneurysm depends on its size. A larger aneurysm has a higher chance of rupturing. In general, the risk of rupture outweighs the risk of surgery when an abdominal aneurysm is wider than 5–5.5 centimeters (a little more than 2 inches) or expands by more than 1 centimeter (a little less than half an inch) in one year.

With successful surgical repair, the prognosis is excellent.

Additional info

American Heart Association (AHA)

National Heart, Lung, and Blood Institute (NHLBI)

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.