What is an aneurysm?
An aneurysm is a bulge in an artery or vein usually caused by a weakening of the vessel wall.
The danger of aneurysms is that they can rupture (burst) because the vessel wall is weakened.
Aneurysms can occur anywhere. But there are two main types that can result in serious outcomes - aortic aneurysms and brain aneurysms (or cerebral aneurysms).
Aortic aneurysms occur in the aorta, which is the main artery that carries blood from the heart to the rest of the body. Brain aneurysms affect blood vessels in the brain.
Aneurysms can be harmless. As long as they don’t rupture, they probably won’t cause any problems.
But if they do rupture, it can be very dangerous, causing bleeding and even death.
Aneurysms can occur at any age but are more common in adults.
Last reviewed: November 2016