What is an aneurysm?
An aneurysm is an abnormal, blood-filled bulge that forms in a weak area of a blood vessel wall. Blood pressure forces the weakened area to balloon outward. This can happen in any part of the body but is most common in the brain, or parts of the aorta, the largest blood vessel in the body. An aneurysm can be fatal if it ruptures and triggers a stroke or massive haemorrhage. If this happens, it must be treated immediately as a medical emergency. Call 999 and ask for an ambulance.
Types of aneurysm
While aortic and brain aneurysms are most common, aneurysms can occur anywhere in the body.
The 5 most common types are:
- Aortic aneurysm - The abdominal aorta is the largest blood vessel in the body, pumping blood from the heart and supplying the rest of the body with oxygen. Normally, the aorta is about the width of a garden hose, but an aneurysm can widen it to more than double its normal size. Aortic aneurysms are most common in men over 65. One in 25 of this age group is affected in the UK and screening for them is available on the NHS.
- Cerebral (brain) aneurysm - This is also known as a cerebral or berry aneurysm and occurs in the weakened wall of a blood vessel in the brain. It’s difficult to estimate how many people are affected overall, as many of these types of aneurysm go undetected. The numbers that actually rupture are about 1 in 12,500 people a year.
- Thoracic aneurysm - may cause pain in the chest, hoarseness, persistent coughing and difficulty swallowing.
- Popliteal aneurysm (aneurysm in leg) - may cause a throbbing sensation or lump directly behind the knee (this type of aneurysm is common in smokers).
- Left ventricular aneurysm - causes a ballooning out of part of the wall of the heart. A previous heart attack most commonly causes a ventricular aneurysm. In rare cases, severe chest trauma can also cause a ventricular aneurysm. Symptoms include irregular heartbeat or blood clots.
Causes and risk factors of aneurysm
The NHS has a screening service in most parts of the UK to check men who are 65 and over for abdominal aortic aneurysms. Elsewhere, GPs can refer anyone for screening who is at an increased risk of having an aortic aneurysm.
The best way to prevent an aneurysm, or lower your risk of an aneurysm getting bigger or rupturing, is to treat high blood pressure, high cholesterol, and diabetes as appropriate, and make lifestyle changes that avoid habits or activities that can damage your blood vessels, such as:
- Poor diet and nutrition
- Lack of exercise or a sedentary lifestyle
- Being overweight or obese