An abdominal aortic aneurysm (AAA) is a bulge or swelling in the aorta, the main blood vessel that runs from the heart down through the chest and tummy.
An AAA can be dangerous if it isn't spotted early on.
It can get bigger over time and could burst (rupture), causing life-threatening bleeding.
Men aged 65 and over are most at risk of AAAs. This is why men are invited for screening to check for an AAA when they're 65.
This page covers:
When to get medical help
Who's at risk
Reducing your risk
AAAs don't usually cause any obvious symptoms, and are often only picked up during screening or tests carried out for another reason.
Some people with an AAA have:
If an AAA bursts, it can cause:
Make an appointment to see your doctor as soon as possible if you have symptoms, especially if you're at a higher risk of an AAA.
An ultrasound scan of your tummy may be done to check if you have one.
Call for an ambulance immediately if you or someone else develops symptoms of a burst AAA.
An AAA can form if the sides of the aorta weaken and balloon outwards. It's not always clear why this happens, but there are things that increase the risk.
People at a higher risk of getting an AAA include:
Speak to your doctor if you're worried you may be at risk of an AAA. They may suggest having a scan to check if you have one and making healthy lifestyle changes to reduce your risk of an AAA.
The recommended treatment for an AAA depends on how big it is.
Treatment isn't always needed straight away if the risk of an AAA bursting is low.
Treatment for a:
Ask your doctor if you're not sure what size your AAA is.
Read more about treatments for AAAs .
There are several things you can do to reduce your chances of getting an AAA or help stop one getting bigger.
If you have a condition that increases your risk of an AAA, such as high blood pressure, your doctor may also recommend taking tablets to treat this.
In England, screening for AAA is offered to men during the year they turn 65. This can help spot a swelling in the aorta early on, when it can be treated.
The test involves a quick and painless ultrasound scan to see how big your aorta is.
If you're a man over 65 and you haven't been screened, you can request a test by contacting your local AAA screening service directly.
Women and men under 65 aren't routinely invited for screening. But if you think you might have a higher risk of an AAA, talk to your doctor about the possibility of having a scan.
Read more about screening for an AAA .
The treatment for an abdominal aortic aneurysm (AAA) mostly depends on how big it is.
AAAs are grouped into three sizes:
Large AAAs are more likely to burst (rupture), so surgery to stop this happening is usually recommended.
The risk of a small or medium AAA bursting is much lower, so you'll normally be advised to have regular scans to check its size and make healthy lifestyle changes to help stop it getting bigger.
Ask your doctor if you're not sure what size your aneurysm is.
You might not need treatment if you have a small or medium AAA. This is because the risk of the AAA bursting is smaller than the risk of complications from surgery.
You'll be asked to come back for regular ultrasound scans to check if your aneurysm is getting bigger.
Scans are done:
Surgery may be offered if your aneurysm becomes a large AAA.
You'll also be told about lifestyle changes that can help reduce the risk of an aneurysm getting bigger, such as eating healthily.
Read more about how to stop an aneurysm growing .
You can otherwise carry on as normal, although having an AAA may have some implications for things such as driving and getting travel insurance.
Read some frequently asked questions about AAAs for more information.
If you have a large AAA, surgery to strengthen it with a piece of man-made tubing (a graft) is usually recommended because the risk of it bursting is bigger than the risk of complications from surgery.
There are two main types of surgery for an AAA:
Both techniques are equally good at reducing the risk of an AAA bursting, but each has its own advantages and disadvantages. Talk to your surgeon about which is best for you.
If surgery isn't suitable for you, you'll have regular scans to monitor your aneurysm and be given advice about healthy lifestyle changes, and you may be prescribed medication to help stop the aneurysm bursting.
In endovascular surgery, a graft is inserted into a blood vessel in your groin through small cuts made in your skin. It's then carefully guided up into the aneurysm.
This is usually done under general anaesthetic , where you're asleep.
You'll normally stay in hospital for two or three days after the operation, and it'll take a few weeks or months to fully recover.
The risk of complications is generally lower than with open surgery, and the hospital stay and recovery time is often shorter. Around 98% of people make a full recovery.
Risks of endovascular surgery include:
Watch a video about endovascular surgery for an AAA.
During open surgery, a cut is made in your tummy and your surgeon replaces the affected section of aorta with a graft. This is done under general anaesthetic.
You'll usually stay in hospital for 7-10 days after the operation, and it'll take a few weeks or months to fully recover.
The risk of complications is generally higher than with endovascular surgery, and the hospital stay and recovery time is often longer. Around 95-97% of people make a full recovery.
Risks of open surgery include:
The risk of graft problems is lower than with endovascular surgery. The graft will usually work well for the rest of your life and you won't normally need regular scans to check it.
Watch a video about open surgery for an AAA.
A burst aneurysm is treated with emergency surgery using the same techniques used for a large aneurysm.
The decision about whether to perform open or endovascular surgery is made by the surgeon carrying out the operation.
Only about 2 in 10 people who have a burst aneurysm survive, which is why an operation to stop an aneurysm bursting is usually recommended if it's large.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.