Mariah- don't worry TOO hard I'm leaving my 20s now and my mom was kinda the same way at first. I was the same way as your son except far less ambitious, I was a skateboarder and am still an avid snowboarder, she would (and still) do the same worrying that you are, but trust me, he's gonna be ok!!!! He's gettin out there and living life . Unfortunatly being into extreme sports has it's injuries along with it, I've had multiple concussions, as long as he got to the doctor and they are looking or looked at him, he should be ok...if he starts vomiting then he should quickly go back...thats about all the advice I can give on the extreme sports topic tho...were strong! And love the thrill...