That startling statistic comes from the Ontario Brain Injury Association, which adds this calming note: Most of these will be mild, and the children will recover with no lasting damage.

However, how can you know if your child has just a bump on the head or a concussion that needs treatment?

The American Academy of Neurology defines a concussion as a change in mental status caused by a head injury. Major symptoms of a concussion include confusion and amnesia. Loss of consciousness may or may not occur.

The academy divides concussions into three types. Grade one is the most common, but also the hardest to diagnose because it happens so quickly. There will be momentary confusion that won't last longer than 15 minutes, and no loss of consciousness. With grade two concussions, there is also no loss of consciousness, but the symptoms of confusion and inattention last longer than 15 minutes. A concussion is considered grade three if there is a loss of consciousness.

Other symptoms of a concussion include headache, vision disturbances, dizziness, loss of balance, ringing in the ears, difficulty concentrating and nausea.

Anyone with a grade two or three concussion needs to be immediately evaluated by a doctor, and should be symptom-free for at least two weeks before returning to sports activities, according to the academy.

More information

To read more, visit the American Academy of Family Physicians.