An aneurysm occurs when part of an artery (the vessel that takes blood away from the heart) swells.  This happens when there is a weak patch in the blood vessel wall. The pressure of blood in the artery being pumped away from the heart causes it to 'balloon' out at the weak point. If they burst aneurysms can be fatal.

What causes aneurysm and who can get it?

Aneurysms can happen in any of the blood vessels in the body, but they most commonly occur in the arteries of the brain and in the largest artery of the body, the aorta. They can affect people of any age or sex but they are most common in men, people with high blood pressure (hypertension) and older people over the age of 65.

Older people are more at risk because aneurysms that occur in larger arteries such as the aorta (the main artery that comes away from the heart) are usually caused by high blood pressure and atherosclerosis. This condition is the build-up of fatty deposit (cholesterol) on the artery walls that causes them to weaken. Anyone can develop atherosclerosis, especially if you eat a diet with too much saturated fat, but it is more common as you get older.

Aneurysms can also be caused by injury, after a bad car crash for example. In young people they can be caused by infection or vasculitis (inflammation of the blood vessel), or may be congenital (something that you are born with), although this is rare.

What are the signs and symptoms of aneurysm?

The symptoms of an aneurysm depend how big it is and where it is in your body. If your aneurysm is small you may not have any symptoms. You might not even know you’ve got it.
However, a large brain (cerebral) aneurysm, for example, can press on nerves in your head causing a loss of feeling in your face or problems with your eyes such as blurred vision and headaches. If a brain aneurysm ruptures, it will cause bleeding in the brain. This can then lead to you losing consciousness and even having a stroke.

How is it normally diagnosed and treated?

Aortic aneurysms are often located in your stomach area and are diagnosed when a GP finds a lump in a person’s abdomen. An ultrasound scan is then used to give a clear picture of its size.

A brain aneurysm can be detected using a special kind of X-ray called an angiogram or arteriogram. This is where special dye is used to show up organs and blood vessels in your body.

Treatment of aneurysms depends on where they are and how big they are. Not all aneurysms are treated at the time they are diagnosed. If it’s not very big your doctor may just have to keep an eye on it to make sure it doesn’t get any bigger.

Surgery is sometimes carried out to stop an aneurysm rupturing (bursting). It may also be performed with a brain aneurysm that has already burst. This is to stop the bleeding and reduce the risk of permanent brain damage.

With an aortic aneurysm, surgical procedure involves replacing the bit of the artery affected by the aneurysm. This is done with a tube made out of a very elastic material – this acts in a very similar way to a normal healthy artery.

What’s going to help?

Most aneurysms are the result of arteriosclerosis that develops as you get older. To prevent getting artherosclerosis, the best thing you can do is to keep healthy so that your blood vessels stay strong.
Exercise regularly, don’t smoke and eat a healthy balanced diet with plenty of fruit and vegetables.

For more help and information

British Heart Foundation

Kids with Heart

Last reviewed by Great Ormond Street Hospital: 16th August 2007

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