The aorta is the largest blood vessel in the human body. It carries blood from your heart up to your head and arms and down to your abdomen, legs, and pelvis. The walls of the aorta can swell or bulge out like a balloon if they become weak. This is called an abdominal aortic aneurysm (AAA) when it happens in the part of the aorta that’s in your abdomen.

AAAs don’t always cause problems, but a ruptured aneurysm can be life threatening. Therefore, if you’re diagnosed with an aneurysm, your doctor will probably want to monitor you closely, even if they don’t intervene right away.

Most aneurysms have no symptoms unless they rupture. If an AAA does rupture, you may experience one or more of the following symptoms:

Contact your doctor immediately if you experience any of these symptoms. A ruptured aneurysm can be life threatening.

AAAs that haven’t ruptured are most often diagnosed when a doctor is scanning or examining your abdomen for another reason.

If your doctor suspects that you may have one, they will feel your stomach to see if it’s rigid or contains a pulsing mass. They may also diagnose one for screening purposes. They may also check the blood flow in your legs or perform one of the following tests:

The cause of AAAs is currently unknown. However, certain factors have been shown to increase your risk for them. They include:

Smoking

Smoking can directly damage the walls of your arteries, making them more likely to bulge. It can also increase your risk of high blood pressure.

High blood pressure (hypertension)

Blood pressure refers to the level of pressure on the walls of your blood vessels. High blood pressure can weaken the walls of your aorta. This makes an aneurysm more likely to form.

Vascular inflammation (vasculitis)

Serious inflammation within the aorta and other arteries can occasionally cause AAAs, but this happens very rarely.

Aneurysms can form in any blood vessel in your body. However, AAAs are considered particularly serious because of the size of the aorta.

AAAs are usually classified by their size and the speed at which they’re growing. These two factors can help predict the health effects of the aneurysm.

Small: (less than 5.5 centimeters) or slow-growing AAAsgenerally have a much lower risk of rupture than larger aneurysms or those that grow faster. Doctors often consider it safer to monitor these with regular abdominal ultrasounds than to treat them.

Large: (greater than 5.5 centimeters) or fast-growing AAAsare much more likely to rupture than small or slow-growing aneurysms. A rupture can lead to internal bleeding and other serious complications. The larger the aneurysm is, the more likely that it will need to be treated with surgery. These types of aneurysms also need to be treated if they’re causing symptoms or leaking blood.

AAAs are more likely to occur if you:

  • are male
  • have overweight or obesity
  • are over age 60
  • have a family history of heart conditions and diseases and aneurysms
  • have high blood pressure, especially if you’re between 35 and 60 years old
  • have high cholesterol or fatty buildup in the blood vessels (atherosclerosis)
  • live a sedentary lifestyle
  • have had trauma to your abdomen or other damage to your midsection
  • smoke tobacco products

Treatment for an abdominal aortic aneurysm may vary depending on your overall health and the size, exact location, growth rate, and type of aneurysm.

Treatment options may include:

  • Open abdominal surgery. This procedure is used to remove damaged areas of your aorta. It’s the more invasive form of surgery and has a longer recovery time, but may be necessary if your aneurysm is very large or has already ruptured.
  • Endovascular surgery. This is a less invasive form of surgery than open abdominal surgery. It involves using a graft to stabilize the weakened walls of your aorta.
  • Monitoring. For a small AAA that’s less than 5.5 centimeters wide, your doctor may decide to monitor it regularly with imaging instead of performing surgery.

If your doctor recommends open abdominal surgery, it may take up to 6 weeks to recover. Recovery from endovascular surgery only takes 2 weeks.

The success of surgery and recovery greatly depends on whether or not the AAA is found before it ruptures. Prognosis is usually good if the AAA is found before it ruptures.

An abdominal aortic aneurysm could cause several complications, which can be serious or even life-threatening.

Potential complications of an abdominal aortic aneurysm include:

  • aortic dissection, or a tear in the inner layer of the aorta
  • blood clots, which could break loose and block blood flow to other parts of the body
  • rupture of the aortic aneurysm, which may lead to internal bleeding

If you experience symptoms like low blood pressure, difficulty breathing, an increased heart rate pulse, or sudden, intense pain in the back or stomach, you should seek medical attention immediately.

Focusing on heart health can prevent an AAA. This means watching what you eat, exercising, and avoiding other cardiovascular risk factors such as smoking. Your doctor might also prescribe medicines to treat high blood pressure or cholesterol or to help you control your diabetes.

Your doctor may want to screen you for an AAA when you turn 65 if you’re at a higher risk due to smoking and other factors. The screening test uses an abdominal ultrasound to scan your aorta for bulges. It’s painless and a quick screening tool.