Someone with a concussion may be knocked unconscious, but this doesn’t happen in every case. In fact, a brief loss of consciousness or “blacking out” doesn’t mean a concussion is any more or less serious than one where a person didn’t black out.
If your child might have had a concussion, go to the emergency room if you see any of these symptoms:
loss of consciousness
severe headache, including a headache that gets worse
confusion and saying things that don’t make sense
unresponsiveness (you can’t wake your child)