Knoxville (WVLT) - An estimated 350,000 athletes experience some kind of head injury while playing sports every year in the US.
And that's only counting the ones who lose consciousness.
A sports concussion can be a ticking time bomb.
They punt, pass and kick. And in the process take a lot of hits.
Sometimes, those hits result in concussions and they happen in almost every sport, at almost every level.
"I have seen quite a few concussions, both at the high school and collegiate level. They're very common in collision sports and contact sports," certified athletic trainer Colin Heenan says many parents aren't aware of what concussions are, or how severe they can be. "No concussion is the same. They may present with a headache, blurry vision, ringing in the ear, memory loss, poor balance, or sensitivity to light."
Studies have found in cases where athletes had three of more concussions over their lifetime, they were five times more at risk for early onset Alzheimer's disease, three times more at risk of significant memory loss and four times more likely to have severely elevated depression.
"Football's going to be probably the sport you see concussions in the most, any other sport, though that involves some sort of contact or collisions, you can see concussions," Heenan says.
In fact, the NFL has made some changes to lessen the impact of head injuries, with rule changes and the gradual elimination of Astroturf.
Officials are also looking at changes in helmets and mouthpieces to lessen the severity of hits to the head.
But not as easily changed is the football player mentality.
From a young age, they're taught to play in pain, sacrifice their bodies and stay on the field to make their coaches happy.
One recent study showed athletes are six times more likely to suffer a second concussion if they return within a week of the first one.
Some sports professionals hope studies like this will intensify the debate and bring about quicker change.