Experts say these dangerous blows to the head can cause problems even years later. There are new reasons why athletes are considering staying in therapy longer.
Female Speaker: From the grid iron to the ball field, to the soccer stadium athletes put their hearts and sometimes their heads into every move. Jonathan Weber: The guy's forehead hit me right in my mouth and my - I blacked out right away. Female Speaker: Sixteen year old soccer star Jonathan Weber suffered a concussion. Jonathan Weber: I got headaches for like a month, a month and a half after. Female Speaker: Before he was allowed back on the field he had to go through two months of rest, rehab and monitoring. Jonathan thought it was overkill, experts say it's necessary. Trent Nessler: You can function, you can remember your name, remember who is present, you are okay to go back to sport, that just not the case anymore. Male Speaker: Spell theory. Jonathan Weber: T H E O R Y. Female Speaker: Physical therapists spend weeks building up his reflexes. Male Speaker: Six minus two. Jonathan Weber: Four. Female Speaker: And work on balance or staring at a disco ball Jonathan has to focus on not falling, his heart rate is monitored weekly, he is not allowed on the field until he can get heart rate up without headaches and nausea. Study show more than 40% of high school athletes who return to action too soon after a concussion. Trent Nessler: Every time you have a concussion you are more susceptible to another concussion. Female Speaker: Returning too soon is also linked to depression, early dementia and in rare cases second impact syndrome where the brain swells causing respiratory failure. Jonathan Weber: I realize that like it could like impact me later on my life. Female Speaker: Sitting on the sidelines it wasn't fun, but Jonathan knows it will payoff even after his high school soccer days are done. I'm Casey Taylor reporting.