Children or teenagers showing signs of concussion shouldn't play sport for at least a fortnight after symptoms have disappeared, doctors warn.
The Australian Medical Association and Australian Institute of Sport have released a joint statement on concussion in sport amid growing concerns about the issue.
It's estimated there are as many as 100,000 sports-related concussions every year, but accurate rates are hard to know because many cases go unreported, AIS chief medical official Dr David Hughes says.
"Concussion in sport is a growing health concern and affects participants at all levels - from children through to elite athletes," Dr Hughes said.
The AIS and AMA recommended that "if in doubt, sit it out".
They have also launched a government-funded website (concussioninsport.gov.au) with tools to help teach athletes, parents, teachers, coaches and medical practitioners about concussion.
Dr Hughes said it wasn't about deterring people from playing contact sport but to make them aware of the warning signs and how to deal with concussion as it can be difficult to diagnose.
Outgoing AMA president Brian Owler says sports-related concussion is a type of brain injury that's not always obvious and symptoms can change over time.
Those under 18 were particularly vulnerable.
"Missing a couple of weeks of playing won't kill them, but letting someone with a brain injury back on to the field - even just the training field - can be disastrous," the neurosurgeon said.
