A concussion is an injury to the brain that comes from a solid hit to the head (such as getting tackled in football) or a shockwave (such as an explosion). Concussion symptoms range from obvious brain injury to very subtle changes in behavior. Researchers aren't completely sure how a concussion works, but it definitely affects the brain's ability to function correctly, at least short term.
Diagnosing a concussion can be complicated. There are several signs or symptoms that can indicate a victim has suffered a concussion. It pays to have someone specifically trained in recognizing concussions to evaluate possible concussion symptoms. These are some red flags (signs of a concussion) to look for after a hard hit on the head:
- loss of consciousness (getting knocked out)
- inability to pay attention
- memory loss (for example, an athlete should know where the game is, what quarter/half it is, who scored last, who the team played last week and which team won the last game he or she played)
- losing balance or coordination
It's not required to have all of these -- or even more than one -- for an injury to the head to be a concussion. Indeed, there's a common misconception that in order for an injury to be a concussion the victim has to get knocked out or not remember what happened, but that is incorrect.
It's one thing to be a little dizzy after hitting your head accidentally and resting until you feel better, but it's something else entirely to go back into a football game and risk another hit.
Don't underestimate the power of a concussion. It may seem like a minor injury, especially if the victim wasn't knocked out. You may think you just "got your bell rung" when a hit on the noggin makes you see stars. However, once a person has suffered a concussion, it's easier to get the next one.
Guskiewicz, K.M., et al. "Research based recommendations on management of sport related concussion: summary of the National Athletic Trainers' Association position statement." Br J Sports Med. 2006 Jan; 40(1): 6–10.
Theye, Fred and Karla A. Mueller. "'Heads Up': Concussions in High School Sports." Clin Med Res. 2004 Aug; 2(3): 165–171.