Jordan Korte didn't feel well when he woke up that morning, a day after a hard check in a hockey game caused him to smash his head on the boards and then on the ice. By the end of the school day in Rochester, he knew something was seriously wrong.

Korte, then a seventh-grader, was in tears when he called his parents.

"My head hurt so bad," he said. "After it happened, I thought I could still play, but I felt like I was going to faint and throw up and collapse. I went to the locker room, and I was shaking. Then the next day at school, with all the noise and the lights, my head was just spinning and pounding."

Before Jordan's injury two years ago, the Korte family knew nothing about concussions. They were surprised to find that many coaches, parents, players, teachers and even some doctors weren't well-versed in dealing with head injuries, either.

Medical professionals have been sounding an alarm about concussions in the wake of research revealing the devastating, long-term effects they can have. But a lack of education, and a hockey culture that celebrates toughness, have made it hard for the hockey community in Minnesota and beyond to reduce the number of concussions and effectively treat them. Among the issues:

• Some players won't report symptoms, fearing a loss of playing time or the appearance of weakness, and some do not know the signs of concussion.

• In youth sports, coaches and parents are typically the first people in contact with a concussed athlete, but some don't know how to recognize a concussion or what to do.

• Some doctors, particularly in emergency rooms, use outdated treatment protocols and might send young athletes back to school or to play too soon.

• Referees don't consistently enforce rules against dangerous hits.

"I think we're making progress in some sectors," said Aynsley Smith, research director of the Mayo Clinic Sports Medicine Center and a leading voice in concussion education and prevention. "But there still are an awful lot of people who grew up being told to just shake it off. I don't think they quite understand the science at this point, so we have to keep pushing."

Lynn and Mike Korte are on board. An emergency room doctor told their son, Jordan, he could return to school immediately and resume playing when his headaches went away. His lingering symptoms led them to Mayo's Sports Medicine Center, where they were told he should have been doing nothing -- no school, no exercise, no TV, no leaving the house -- until a doctor cleared him.

"It was very scary, very eye-opening," Lynn Korte said. "We were so uneducated. It was a shock to us to learn how serious this is."

Many are poorly informed Jordan Korte is 15 now, a freshman at Mayo High School and a defenseman on his Bantam A team. He still has two or three mild headaches a week, the residual effect of his hockey concussion and another he got 18 months later playing baseball.

A concussion happens when an impact to the head causes the brain to collide with the skull. As nerves stretch and tear, the chemical balance of the brain is altered; until it repairs itself, which takes time, its function can be impaired and it is highly vulnerable to further injury.

Korte immediately felt nauseated and unsteady, two common symptoms of concussion. Other symptoms might not be immediately evident, which is why doctors stress caution with any blow to the head. Children's developing brains are more susceptible to injury, and "second-impact syndrome" -- another concussion suffered before the first is fully healed -- can lead to serious brain damage or death.

Though Korte tried to reenter the game after sitting out a shift, brain-injury experts say players should not return to play or practice on the same day if they exhibit symptoms of concussion. The motto "When in doubt, sit them out" has become a battle cry among those advocating for better education about the effects of concussions. It also has become law in nine states to require written clearance from a medical professional before athletes 18 and younger can return to their sport after a head injury.

Still, many people in sports remain poorly informed about concussions. Many do not know the brain requires complete rest to heal properly, and that it might not be fully recovered even after symptoms disappear. For a week after his concussion, Korte attended school, unaware that cognitive exertion was stressing his brain as much as physical exertion -- and that it was preventing him from getting better.

The Mayo Clinic staff told Korte to stay home from school and away from his computer, telephone, TV, video games and anything else that required mental effort. His family kept the blinds closed throughout the house, because he couldn't stand light.

His mother also noticed that during the two weeks Jordan remained inactive and housebound, his normally upbeat demeanor took a downward turn.

"I was mad," he said. "And it was hard when I saw the guys at school. They'd be like, 'Are you playing today?' And I had to keep saying, 'Nope.' I went to a tournament, and when we were losing, all I could think about was, 'If I was out there, what could I have done to make a difference?'"

That is a common attitude among players. Many deny or downplay concussion symptoms because they don't want to sit out, which can be reinforced by a hockey culture that celebrates those who "play hurt."

During the 2009-10 season, researchers asked independent observers to follow two Canadian junior hockey teams to determine concussion rates. They recorded 21.5 concussions per 1,000 man-games, seven times the rate of a 2005 study of NCAA men's hockey teams that self-reported. The study also noted extensive pressure from parents and coaches to keep players on the ice, as well as a reticence among players to admit symptoms.

Jim Johnson, a New Hope native who spent 13 seasons as an NHL defenseman, retired after his ninth concussion. When he was coaching a bantam AAA team of 13- and 14-year-old boys in Arizona, Johnson held a concussed player out of a game, only to incur the wrath of a father who accused him of "wrecking his son's career."

"I'm overwhelmed by the amount of pressure players place on themselves and that parents place on players," Johnson said.

Officials struggle to adapt Officials can feel pressure, too, when they try to enforce rules. Longtime NHL referee Kerry Fraser said despite strong statements about ridding the game of dangerous hits that cause head injuries, coaches and league administrators don't uniformly support the effort.

Fraser said that twice, when he assessed major and game-misconduct penalties for reckless hits, those penalties were overturned by the NHL. He said he has received death threats and routinely sees youth hockey officials harassed for enforcing rules.

"We have a culture that has evolved in this game that needs to change," Fraser said.

Hal Tearse, coach of the boys' team at Providence Academy, has seen similar issues in youth and high school games. As coach-in-chief of Minnesota Hockey, which oversees youth and amateur hockey in the state, he asked officials in December to crack down on contact to the head and hits from behind -- two major causes of concussions. Because the officials didn't want to be too harsh, which would invite anger, Tearse said they sometimes called lesser penalties when they saw more dangerous infractions.

"That takes all the teeth out of the rules," Tearse said. "In the competitive arena, you always have people who don't want penalties called too tight, the old 'let the boys play.' In high school, they won't ring these kids up. But the games are so physical, and with the size mismatches, kids get hurt."

Returning slowly is key In the emergency room, Jordan Korte was told he could return to hockey as soon as his headaches stopped. The latest treatment protocols, however, say an athlete should follow a gradual path back to full practices and games -- starting only after all symptoms have disappeared.

The Mayo Clinic's sports medicine center told Korte to follow that progression, and he soon understood why.

"A month after the concussion, I tried to go back and practice, because the headaches weren't as bad," he said. "I was passing to guys and missing them by 5 or 6 feet, and I was shooting way wide of the net. I was not functioning whatsoever."

Korte didn't return to play for six weeks, and he missed one week of school. Other players, though, might not follow or even know about the step-by-step return. Though it is recommended by organizations such as Minnesota Hockey and the Minnesota State High School League, they cannot enforce its use, and coaches are not required to complete any training about concussions.

Lynn Korte said Jordan's coaches and teachers were supportive of his gradual return, but she wonders whether the messages are getting through to everyone.

"In Rochester, they're starting to make a push, but I still don't think there's enough being done," she said. "Until you have one, I just don't think it makes an impact on people."

Awareness, understanding Jordan's experience led him to learn more about concussions, which led to a project for his school science fair. He built a batting helmet designed to guard against concussions, fitting a regular helmet with padding made by military supplier Team Wendy.

He was not wearing it when he was pitching batting practice last summer. A batted ball hit Korte in the side of the head, and as the sunlight and the chatter began to bother him, he knew he had another concussion.

He and his family also knew what to do.

"I was like, 'Oh, no, here we go again,'" he said. "But this one wasn't as bad. We went to the sports medicine clinic and ran through the tests. I laid low for a week, and I was back playing in two weeks."

Korte now wears helmets for any risky activity, including sledding and boot hockey. His family never had used bike helmets, but Lynn insists they all wear them now.

Their experience has even changed their vocabulary.

"The night Jordan got his concussion, his dad said, 'I think he just got his bell rung,'" Lynn Korte said. "That's how we all grew up thinking about it. I can guarantee you, we don't say that anymore."