Is there a blood test that can diagnose a concussion or mild TBI?

FDA-cleared blood tests measuring GFAP and UCH-L1 help emergency doctors decide who is at higher risk for brain injury and who may need imaging. They are not a simple yes-or-no «concussion test.» They are used primarily in the first hours after injury and represent one piece of information alongside symptoms, exam findings, and imaging. If you did not receive a blood test at the time of injury, other evaluations may still help document a brain injury later.