Could you tell me what happens when you have blood clots in your brain?

More info needed: It would depend on the size and location of the clot. It would also depend on its cause. Trauma, stroke or the use of blood thinners are just some of the potential causes. It is usually a very serious conditon.

Stroke: What is commonly referred as blood clots may represent two (totally different) serious categories: hemorrhage or ischemia. In hemorrhage the blood leaks out of the blood vessels and accumulates inside the brain or between the brain and the skull. In ischemia the blood flow is interrupted blocking the oxygen supply to the brain. The brain damage resulting from either ranges from mild to fatal.