Most likely they will give you an MRI or CAT (or maybe CT?) scan. Basically you lie on a board and then they make the board move backwards into a sort of giant tube. The tube scans your brain for a concussion, and you move slowly out. It only takes a few minutes and isn't dangerous or painful (or anything; you can pretty much nearly fall asleep while they are scanning).
Here's a picture:
![]()
Once they get the results, they can tell you if you have a concussion or not. Basically, a concussion is an injury to the brain. If you hit your head or something like that, then you could have a concussion. Did you hit your head? Is that why you are having painkillers prescribed for you?
They're not going to waste a CT scan on a concussion, you get huge amounts of radiation from them.
Besides, there isn't really any treatment for concussions, doctors just want to confirm you haven't suffered more serious brain trauma, and tell you to stay away from activities where you could re-concuss yourself.