Abdominal aortic aneurysm screening

Abdominal aortic aneurysm (AAA) screening is a way of checking if there's a bulge or swelling in the aorta, the main blood vessel that runs from your heart down through your tummy.

This bulge or swelling is called an abdominal aortic aneurysm, or AAA. It can be serious if it's not spotted early on because it could get bigger and eventually burst (rupture).

Who's screened for AAA

In England, screening for AAA is offered to men during the year they turn 65.

Men aged 65 or over are most at risk of AAAs. Screening can help spot a swelling in the aorta early on when it can be treated.

Screening for AAA isn't routinely offered to:

• women
• men under 65
• people who've already been treated for an AAA

This is because the risk of an AAA is much smaller in these groups.

You can ask for a scan to check for an AAA if you think you might need one but haven't been offered a screening test.

How to get screened for AAA

If you're a man and you're registered with a GP, you'll get a screening invitation in the post when you're 64 or soon after your 65th birthday. You can then arrange an appointment that suits you.

If you're a man over 65 and you haven't been screened before, you can ask for a test by contacting your local AAA screening service directly.

If you're a woman or man under 65 and you think you might have a higher risk of AAA – for example, because a close family member has had one – talk to your GP about the possibility of having a scan to check for an AAA.

If your GP thinks you might benefit from having a scan, this will usually be done when you're five years younger than the age at which your relative was found to have an AAA.

Benefits of AAA screening

An AAA will often cause few or no obvious symptoms, but if it's left to get bigger it could burst and cause life-threatening bleeding inside your tummy.

About 8 in every 10 people who have a burst AAA die before they get to hospital or don't survive emergency surgery to repair it.

Screening can pick up an AAA before it bursts. If an AAA is found, you can then choose to have regular scans to monitor it or surgery to stop it bursting.

The screening test is very quick, painless and reliable. Research suggests it can halve the risk of dying from an AAA.

Deciding to be screened

It's up to you to decide if you want to be screened for AAA. While there are clear benefits of screening, you should also consider the possible risks.

There's no risk from the screening test itself, but there is a risk of:

• anxiety from being told you have a life-threatening condition
• serious complications of surgery carried out to treat an AAA

You'll get a leaflet with your screening invitation to help you make a decision. You can also read a decision aid leaflet online.

Call your local screening service and ask to be removed from its list if you don't want to be screened.

What happens during AAA screening

Screening for AAA involves a quick and painless ultrasound scan of your tummy.

This is similar to the scan pregnant women have to check on their baby.

When you arrive for your appointment, a screening technician will check your details, explain the scan and ask if you have any questions.

For the scan:

• you lie down on a table and lift up or unbutton your top (you don't need to undress)
• the technician rubs a clear gel on your tummy and moves a small handheld scanner over your skin – pictures from the scanner are shown on a monitor and the technician will measure how wide your aorta is
• the gel is wiped away and you pull down or button up your top
• the technician tells you the result straight away 

The whole test usually takes about 10-15 minutes.

Sometimes the technician might not be able to see your aorta clearly. This isn't anything to worry about. If this happens, you'll be asked to have another scan, usually on a different day.

Results of AAA screening

You'll be told your result at the end of the test. If any problem is found, you'll also be a sent letter confirming the result and letting you know what happens next.

There are four possible screening results.

Normal

A normal result means your aorta isn't swollen (it's less than 3cm across) and you don't have an AAA. More than 98% of men screened have a normal result.

If your result is normal, you won't need any further scans or treatment because an AAA grows slowly and the chances of you developing one after 65 are very small.

Small AAA

If you have a small AAA, this means your aorta measures 3cm to 4.4cm across. Just over 1% of men screened have a small AAA.

You won't need any treatment at this stage as the chance of the AAA bursting is small. You'll be invited back for a scan every year to check its size. Treatment will usually only be needed if it becomes a large AAA.

You'll also be given advice on how you can stop an AAA getting bigger, such as stopping smoking, eating healthily and exercising regularly.

Read a leaflet on small AAA (PDF, 2.3Mb) for more information.

Medium AAA

If you have a medium AAA, this means your aorta measures 4.5cm to 5.4cm across. About 0.5% of men screened have a medium AAA.

You won't need any treatment at this stage as the chance of the AAA bursting is small. You'll be invited back for a scan every three months to check its size. Treatment will usually only be needed if it becomes a large AAA.

You'll also be given advice on how you can stop an AAA getting bigger, such as stopping smoking, eating healthily and exercising regularly.

Read a leaflet on medium AAA (PDF, 2.3Mb) for more information.

Large AAA

If you have a large AAA, this means your aorta measures 5.5cm or more across. About 0.1% of men screened have a large AAA.

As large AAAs are at the highest risk of bursting if left untreated, you'll be referred to a specialist surgeon within two weeks to talk about your treatment options.

Most men with a large AAA are advised to have surgery to stop it getting bigger or bursting.

While surgery carries a risk of serious complications, this is generally smaller than the risk of not treating a large AAA.

Read a leaflet on large AAA (PDF, 2.2Mb) for more information and read about how a large AAA is treated.

More information about AAA screening

For more information, the AAA Screening Programme has guides about:

• AAA screening (PDF, 5.3Mb)
• AAA screening: an easy read guide (PDF, 483kb)
• AAA screening: an audio guide

The GOV.UK website also has AAA screening leaflets in other languages.