Aneurysm Sites

Although aneurysms can occur anywhere where there is a blood vessel, they are most commonly found in arteries.

Aortic Aneurysm

Aortic aneurysms are a swelling of the aorta, usually in a location that has an underlying weakness in the wall. They are usually fusiform in shape and affect the entire circumference of the aorta. Whilst most intact aortic aneurysms do not produce symptoms, they carry an enormous risk of rupture, which may cause a massive or fatal haemorrhage. The main affected site is the lower aorta (termed abdominal aortic aneurysm or AAA), although the upper aorta may also be affected (thoracic aortic aneurysm).

Cerebral Aneurysm

Also known as a brain aneurysm, this disorder occurs when a weakness in the wall of a cerebral artery or vein causes a localised ballooning of the blood vessel. The majority of cerebral aneurysms occur in the arteries at the base of the brain, known as the Circle of Willis. Although cerebral aneurysms may be discovered in a number of ways (see Diagnosis), unfortunately they are normally found when the aneurysm ruptures into the surrounding area causing a subarachnoid haemorrhage.

Other Locations

Aneurysms may also occur in the legs, particularly in the deep vessels such as the popliteal vessels in the knee. Although arterial aneurysms are far more common, venous aneurysms may also develop; for example, popliteal venous aneurysm.