Most people thing you need to lose consciousness or pass out in order to have a concussion. Not at all true. The majority of concussions, 90 percent of them, there is no loss of consciousness at all. Instead, the symptoms are really vague. You might have vision changes, blurry vision, seeing spots; or you might have changes in what you hear. You may have ringing in the ears. Some kids are just confused or have difficulty concentrating. It can be really subtle. The most important things for parents and kids to know about concussions is that when you have one, you shouldn't be on the field. You shouldn't be participating in sports. That's because a concussion is a brain bruise. What's happened is your brain has banged against the skull and you've gotten swelling and inflammation in one part of your brain. If you go out and play and hit your brain again, the swelling and inflammation is much worse. Sometimes the repercussion of a second concussion are very dire. That's incredibly rare. More often, what happens is that you have cumulative effects, so the brain takes longer to heal. We now know, when we have professional athletes that have had multiple concussion over their lifetime, that there are very serious long-term repercussions; including profound depression, in some professional athletes. My best advice is that you teach your kids what the signs of concussion are. If your child thinks that he has suffered a concussion, they need to be taught to sit out. A coach should be supporting this. A parent should be supporting this. Most importantly, a kid should be able to say, "I can't see correctly. I'm not hearing correctly. I'm confused. I'm dizzy. I'm sitting out." Because if you play with a concussion, the likelihood of more serious injury, goes up.