What is Abdominal Aortic Aneurysm?

An abdominal aortic aneurysm (AAA) is a bulge or swelling in the aorta, the main blood vessel that runs from the heart down through the abdomen, most commonly occurring in older adults, particularly men who have smoked. Most aneurysms grow slowly and cause no symptoms, which is why screening programmes exist to detect them before they become dangerous.

The main risk is that a large aneurysm can rupture, causing life-threatening internal bleeding — this is why aneurysms are monitored regularly once found, with surgery considered once they reach a size where the risk of rupture becomes significant.