The dangers of life in the National Football League made headlines in 2009, when a study commissioned by the NFL found that retired players were 19 times more likely than other men of similar ages to develop severe memory problems. The obvious culprit: continued play after repeated head injuries. Indeed, head injury can imitate many types of neurodegenerative disease, including Parkinson’s disease and, as journalist Jeffrey Bartholet reports in “The Collision Syndrome,” on page 66, perhaps even amyotrophic lateral sclerosis, commonly referred to as Lou Gehrig’s disease.

The problem is not unique to professional sports. About 144,000 people aged 18 and younger are treated every year in U.S. hospital emergency rooms for concussions, according to a December 2010 analysis in the Journal of Pediatrics. Nearly a third of these injuries occur while kids are playing organized sports. Forty percent of pediatric concussions seen in emergency rooms involve high school students. The figure is slightly higher—42 percent—for younger children. Overall, concussions are most common in football and ice hockey, followed by soccer, wrestling and other sports, and slightly more boys than girls suffer concussions.

Despite the prevalence of brain injury from kindergarten to high school, relatively little research on the long-term health consequences of concussion has been conducted on child athletes, compared with those in college and in the pros. Scientists have an incomplete understanding of what happens when a child’s brain slams up against the inside of the skull during a blow to the head and how this affects neurological development. As participation in sports continues to grow (1.5 million youngsters now play on football teams in the U.S.), more head injuries are inevitable, making pediatric concussions an emerging public health crisis.

Doctors and public health experts are concerned about the effect of repeat concussions that occur before the brain has had a chance to heal from a prior impact. More research on how they affect younger brains is urgently needed. In addition, coaches, parents and school officials need to pay closer attention to what is already known about the hazards of concussions and how best to prevent permanent damage. (Visit for comprehensive information, including videos, on the topic.)

Most people assume, for instance, that loss of consciousness is the defining feature of all concussions. Yet “seeing stars,” headache, nausea, dizziness, confusion, irritability, and an inability to remember events before or after the injury are the most common symptoms. Because people don’t recognize these warning signs, however, youngsters may continue to play when they should not.

Similarly, because the most obvious symptoms usually disappear within a few minutes to hours, children often return to normal activities too quickly, which overtaxes their injured brain. Depending on age and symptoms, children should not take part in intense physical activity for several weeks to months after a concussion. Even the added neural exertion from mental activities like reading and video games can interfere with the cerebrum’s ability to heal—particularly in the first 24 hours after injury.

Some efforts to protect young brains may actually backfire. In football, hockey and other contact sports, protective headgear seems to have increased the risk of concussion by providing a false sense of security that encourages athletes to hit harder with their head. Helmets do, however, protect against skull fracture.

To address the concussion problem, more states could follow the example of Minnesota. Legislators there passed a law, which took effect in 2011, that requires coaches to undergo training to recognize concussions and mandates the immediate removal from a game of any player at the first sign of dizziness or confusion. He or she can return to sports only with a doctor’s authorization. The law could have the unintended effect of giving kids an incentive to hide their symptoms. The way around that problem, of course, is for schools, sports leagues and other organizations to join public health experts in raising ever greater awareness among coaches, parents and children to play it smart and take brain injury very seriously.