What is a Concussion? Concussion is a traumatic brain injury that happens when the brain is violently shaken. It can happen during rapid change of movement or when taken a direct hit to the head. The injury can cause lasting effects on the brain. Only about 10% of concussion involve loss of consciousness, so loss of consciousness should not be your deciding facture on if you have a concussion or not. Concussions can cause physical, cognitive, behavioral problems, which can