Abdominal aortic aneurysm Popliteal aneurysm An aneurysm is a swelling in an artery caused by the pressure of blood on a weakened area of artery wall.
Most aneurysms are associated with the narrowing and weakening of arteries due to fatty deposits (atherosclerosis), but they may also sometimes be due to an injury or a genetic disorder that weakens artery walls.
Aneurysms are more common in men, and the risk of developing them increases with age. Other risk factors include high blood pressure, an unhealthy lifestyle, and having a close relative who has, or has had, an aneurysm. Aneurysms can occur in any artery, but they most commonly affect the aorta (the body’s main artery) or cerebral arteries supplying the brain. Popliteal aneurysms, which affect the popliteal artery around the knee, are also relatively common.
Most aneurysms do not cause symptoms. However, if an aneurysm is very large, it may case pain or a pulsating sensation.
If an aneurysm ruptures, it may cause massive internal bleeding. A form of aneurysm known as a dissecting aneurysm is particularly prone to rupture.
An aneurysm may not need treatment, but should be monitored. Emergency surgery is needed for a rupture, and surgery may be advised for a large aneurysm or one liable to rupture