It is hardly a comforting sight when an athlete’s body lies splayed and twisted on the field after an injury. Doctors can splint a broken arm or X-ray a twisted knee. But when a concussion occurs, diagnosis is not so simple.

“The athletes don’t appear injured,” said Dr. Jeffrey Kutcher, assistant professor at Michigan NeuroSport at the University of Michigan. “Concussion is an invisible injury in a lot of cases, therefore there is no awareness of the injury.”

It is a dangerous paradox: Concussion, an injury where the brain is jostled so hard that can cause brain damage, is invisible – almost impossible to accurately diagnose.

Against that backdrop, the American Academy of Neurologists is releasing updated guidelines today designed to make diagnosing concussion at sporting events easier. According to an AAN statement, “catastrophic results can occur and the long-term effects of multiple concussions are unknown.”

The guidelines issued by AAN echo what has been discussed at recent congressional hearings, and at the state level, where laws are being shaped to address youth concussion. There are five tenets to the new AAN guidelines:

1) Any athlete who is suspected to have suffered a concussion should be removed from participation until he or she is evaluated by a physician with training in the evaluation and management of sports concussions;

2) No athlete should be allowed to participate in sports if he or she is still experiencing symptoms from a concussion;

3) Following a concussion, a neurologist or physician with proper training should be consulted prior to clearing the athlete for return to participation;

4) A certified athletic trainer should be present at all sporting events, including practices, where athletes are at risk for concussion;

5) Education efforts should be maximized to improve the understanding of concussion by all athletes, parents, and coaches.

According to the Centers for Disease Control and Prevention, there are 3.8 million sports-related concussions concussions each year in the U.S. That amounts to nearly 4 million invisible injuries every year.

Kutcher stresses that managing a suspected concussion on the playing field is not merely about rote adherence to guidelines, but taking into consideration an athlete’s family history and previous injuries. As understanding of concussions’ long-term effects grows clearer, a clear set of guidelines for coaches and parents is important, said Kutcher.

“We are starting to understand more and more that concussions may have some very serious long-term consequences,” said Kutcher, chairman of the sports neurology section of the AAN and lead author of the concussion guidelines. “As that understanding grows and develops we can’t wait for all the science to tell the complete story. We need common sense reccommendations that should be followed.”