I Have An Indent On The Top Right Side Of

I have an indent on the top right side of my head I have had it for a few years now . I don't no how it got there but as a kid my head got hit by the edge of a door. I'm not sure if that has any thing to do with that but it's pretty big and deep it's about 2 inches long and 2 1/2 wide. I just want to know if it can cause any damage because the back of the indent is hurting right now. I can feel my brain throbbing were it is. I'm 16 years old,