Abdominal aortic aneurysm (AAA) screening is a way of detecting a dangerous swelling (aneurysm) of the aorta – the main blood vessel that runs from the heart, down through the abdomen to the rest of the body. This swelling is far more common in men aged over 65 than it is in women and younger men, so men are invited for screening in the year they turn 65. An AAA usually causes no symptoms, but if it bursts, it’s extremely dangerous and usually fatal. Around 8 out of 10 people with a ruptured AAA either die before they reach hospital or don’t survive surgery. Read more about abdominal aortic aneurysm.