https://www.sciencenewsforstudents.org/article/concussions-leave-clues-in-the-blood
This article got into the details of the study of how many male athletes that do non-contact sports and contact sports get concussions. They also study and are trying a theory of how we can diagnose whether you have a concussion or not. The theory is that after a player has suffer a injury whilst playing a sport that the proteins in their blood would rise to a higher level than players that have not been injured. In hypothesis, if the players proteins rises when they suffer from a injury then they have suffered from a type of brain injury.