Daredevil Johnny Knoxville makes a decent—if often disturbing—living by filming himself in harm’s way. It’s no shock, then, that the co-creator of “Jackass” has had his share of head injuries. Dealing with a concussion, though, is no laughing matter.

Dr. Mickey Collins, assistant director of the Sports Medicine Concussion Program at the University of Pittsburgh Medical Center, believes that every hit to the head should be taken seriously. “I played sports,” he says. “I understand the competitive nature of playing sports and trying to get back on the field, [and] I respect that. In fact, that is my goal: to get kids back to playing.”

Collins says the first step to a diagnosis is communicating with the athlete after an injury. “It’s not like they have a cast on their head,” he says. “It is something that can really go under the radar.”

An athlete may choose to keep a head injury under wraps for various reasons—not wanting to get taken out, fear of losing a starting spot, and not wanting to disappoint the team, to name a few. But “if the athlete chooses to play through these symptoms [headaches, nausea, vision problems, loss of memory, etc.], recovery is going to take a lot longer,” Collins says, adding that, in rare cases, “there could be permanent damage, even death.”

Collins stresses the importance of rest and recovery, and he doesn’t mean taking a day off and suiting back up like when your dad was playing football with a leather helmet. “Recovery from concussions is highly variable,” Collins says. “It may take a day, it may take a year…We do expect an athlete to get better, but there is so much individual variability.”

The only sure way to assess damage and judge recovery is to undergo a medical evaluation. Otherwise, you’re following too closely in the footsteps of Johnny Knoxville, and that probably won’t keep you on the active roster.