Got hit in the face with a volleyball? how do you know if you have a concussion?

LOC: If that blow knocked you unconscious, you had a concussion. Without loss of consciousness (loc), you did not have a concussion.

?concussion: Symptoms of a concussion include confusion, brief loss of consciousness or orientation. Lack of memory of the events in question and for a brief time before the injury and after the injury. Lack of coordination, headaches. If you experience any of these symptoms, see your doctor.