A cerebral aneurysm is a swollen bulge or “ballooning” in the wall of a blood vessel in the brain. A small aneurysm often causes no symptoms. But if it grows, an aneurysm can press on nerves inside your brain, causing pain and other symptoms. It can also leak blood or burst, causing a sudden, severe headache.
A burst aneurysm is a very serious, life-threatening emergency that needs to be treated right away. It leads to a bleeding (hemorrhagic) stroke. A “stroke” is the term doctors use when a part of the brain is damaged because of a problem with the blood vessels in the brain.