An abdominal aortic aneurysm (AAA) is a swelling (aneurysm) of the aorta the main blood
vessel that leads away from the heart, down through the abdomen to the rest of the body.
The abdominal aorta is the largest blood vessel in the body and is usually around 2cm wide
roughly the width of a garden hose. However, it can swell to over 5.5cm what doctors class
as a large AAA.
Large aneurysms are rare, but can be very serious. If a large aneurysm bursts, it causes huge
internal bleeding and is usually fatal.
The bulging occurs when the wall of the aorta weakens. Although what causes this weakness is
unclear, smoking and high blood pressure are thought to increase the risk of an aneurysm.
AAAs are most common in men aged over 65. A rupture accounts for more than 1 in 50 of all
deaths in this group.
This is why all men are invited for a screening
test when they turn 65. The test involves a simple ultrasound scan, which
takes around 10-15 minutes.
In most cases, an AAA causes no noticeable symptoms. However, if it becomes large, some
people may develop a pain or a pulsating feeling in their abdomen (tummy) or
persistent back pain.
An AAA doesn't usually pose a serious threat to health, but there's a risk that a larger
aneurysm could burst (rupture).
A ruptured aneurysm can cause massive internal bleeding, which is usually fatal. Around 8 out
of 10 people with a rupture either die before they reach hospital or don't survive surgery.
The most common symptom of a ruptured aortic aneurysm is sudden and severe pain in the
abdomen.
If you suspect that you or someone else has had a ruptured aneurysm, call 999 immediately and
ask for an ambulance.
Read more about the symptoms of an AAA.
In most cases, an unruptured abdominal aortic aneurysm (AAA) will cause no symptoms, unless
it becomes particularly large.
Symptoms of an unruptured AAA may include:
a pulsating feeling in your stomach (abdomen), usually near your belly button,
that’s usually only noticeable when you touch it
persistent back pain
persistent abdominal pain
If you have any of the symptoms above, you should see your GP as soon as possible.