HACKENSACK, N.J. (CBSNewYork) — Kids are back to school and that means young athletes are back on the field again.

And while fall sports are a good time, they do come with a risk.

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“It’s not just the big hits it’s the little hits the kid falling the goalie hitting the ground or something,” said Hackensack High School athletic trainer Danielle Skiba.

Skiba says concussions are very common and can often go unnoticed.

“It’s honestly every day and it’s not just football it’s football soccer volleyball all the sports,” Skiba tells CBS2’s Reena Roy. “Symptoms can last for a lifetime so it’s not something to play with.”

Concussions are very serious, can get paralyzed, lose memory,” said Hackensack High School soccer player Vance Vivar.

That’s why the Centers for Disease Control and Prevention released updated guidelines for children’s concussions, urging people to look out for symptoms like headaches, dizziness, light sensitivity and sleep problems.

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“If I feel dizzy or anything I try to sit out so I don’t get any further damage,” Vivar said.

The CDC says those symptoms often go away within 1-3 months. But more serious ones like vomiting, severe head pain and unconsciousness should be reported to a doctor immediately and may warrant a CT scan.

“Usually there are clinical signs that a more severe intracranial injury has taken place, at least when used in concert can obviate a need for a CT scan,” Director of Brain Injury Research Center at Mt. Sinai Dr. Kristen Dams-O’Connor said.

The new guidelines warn against blood tests and x-rays in detecting concussions, saying they’re not effective. Experts say the best treatment is to rest, but not for too long — more than 3 days of inactivity can actually worsen symptoms.

The CDC says it’s also important to know that recovery time is different for every person. Children who go undiagnosed are at risk for another concussion and take longer to fully heal.

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It’s estimated at least one million children a year suffer concussions.