Girls have a higher risk for concussions than boys who play the same sport – and a new study in the American Journal of Sports Medicine says female athletes also have more symptoms and take longer to bounce back from these head injuries than boys. So do younger girls compared to older girls.

The Healthy Kids Blog turned to Prithvi Narayan, M.D., chief of neurosurgery at St. Christopher's Hospital for Children in Philadelphia, to understand why this is happening – and to find out what parents, coaches and athletes can do. Over 1.6 million Americans suffer a sports-related concussion every year; a growing number are high school and college athletes.

Why would girls have more concussions, more symptoms and take longer to heal than boys?

There are two possible reasons. One theory is that because girls usually have smaller, more slender necks with smaller neck muscles, their heads may wobble more if they hit their heads or are heading the ball in soccer. That could raise risk for a concussion and for more severe symptoms. The second theory is that female athletes report concussions and symptoms more often and more accurately than boys do. They may be less likely to just shake it off and get back in the game or the practice – something that was ingrained in male athletes for decades before we knew that a potential concussion needs to be taken seriously.

Which sports have a higher risk for concussions in girls?

Soccer is one, in large part due to heading the ball. Basketball is second, according to research from the National Children's Hospital in Columbus, Ohio. Girls' lacrosse comes in third – and has a higher risk for head injuries because girls don't wear helmets. (This is because checking is banned in women's lacrosse.) Helmets really don't protect against concussions, but can cut risk for skull fractures and bleeding in the brain. Cheerleading also has its share of concussions – it's not pompoms on the sidelines anymore. Girls are doing very gymnastic routines with flips and tumbles. Any time you fall and hit your head, or something else hits your head – another player, a ball, a stick – you're at risk for a concussion. And it doesn't even have to be a hit to the head. Being hit on any part of neck or shoulders -- anything that causes brain to shake – can cause one.

What should happen if an athlete – girl or boy – gets hit in the head during a game or practice?

Players, coaches and parents should know the signs of a potential concussion. A player may pass out – but you can have a concussion without passing out. Warning signs include feeling dazed, dizzy, or lightheaded; memory loss; nausea or vomiting; a headache; blurry vision and light sensitivity; speech that's slurred; saying things that don't make sense; difficulty concentrating or thinking; trouble with coordination or balance. A suspected concussion should be evaluated by a doctor. If a player's been hit, they should leave the game. If a parent or another player sees an athlete suffer a head injury that a coach doesn't see, they should tell the coach right away.

What happens next?

It can seem tough on a kid who wants to get back in the game, or who wants to play the next big game or finish the season. But after a concussion the brain needs rest in order to recover. Without that, the brain can't recover properly and a child or teen could be facing lasting changes. At first, it's important to let the brain "cool" – no TV, texting, video games. And the American Academy of Pediatrics recommends not returning to contact sports for four weeks from the date of the concussion. It's really important to avoid a situation where a kid has a second or third concussion in the same season. Some kids even switch sports – going from a contact sport to something like tennis or swimming.

What do researchers want to learn about concussions in teens and younger athletes?

Most studies have been done in college athletes and in professional players, such as pro football players, hockey players and boxers. We want to know what happens in younger brains after a concussion. You can't see the evidence on a regular MRI or CT scan. We're collaborating with doctors in the Princeton Health System to start using special techniques to scan the brains of kids who've suffered concussions.

What about you? Any experience with concussions with your family and friends?