An aneurysm is a bulge in a blood vessel wall. The bleeding from a rupture can cause one type of stroke. The lifestyle tips to prevent both are very similar. They’re both dangerous—and sometimes deadly. They can happen at any age. And they both can cause permanent damage to the brain. So it’s no wonder people get confused about the differences between a stroke vs. aneurysm. “Strokes and cerebral aneurysms are terms you hear often and many people aren’t entirely clear what they mean,” says neurologist Jessica Carpenter, MD. “Both are conditions that involve blood vessels in the head.