-- LOUDON, N.H. -- Dale Earnhardt Jr. made the decision to see a doctor, which he knew could affect whether he races again this year -- or ever.
Earnhardt has suffered concussions in the past. He even missed two races in 2012 following two concussions in a six-race stretch, so the 41-year-old could be a little more aware of the dangers and symptoms of this type of injury.
But even Earnhardt said as late as Tuesday that he thought the headaches and pressure he was experiencing were more likely caused by allergies or a sinus infection than a concussion. And so far, the official diagnosis is he's suffering from concussion-like symptoms, not a concussion. And he has admitted to having raced with concussion-like symptoms in the past.
"Because of my symptoms and my history with concussions, and after my recent wrecks at Michigan [on June 12] and Daytona [on July 2], I reached out and met with a neurological specialist," Earnhardt said Thursday. "After further evaluation, they felt it was best for me to sit out."
Although his team and NASCAR applauded Earnhardt for making the decision, the questions remain: Will other drivers follow his lead if they have concussion-like symptoms, and does NASCAR need to do more?
Are there other drivers who have been hit hard but are driving around New Hampshire Motor Speedway this weekend, when they may be suffering from a concussion that should put them on the sideline with Earnhardt?
NASCAR spokesman David Higdon said the data recorders from the Michigan and Daytona wrecks did not raise any immediate red flags as far as the G-forces in those accidents, where Earnhardt was able to drive away and therefore not seek medical attention.
NASCAR does not have a threshold of G-forces at which a driver is required to see a neurologist. The question is, should the organization have such a rule? And should drivers who have had a history of concussions be scrutinized more after accidents?
IndyCar has found its threshold for concussion is somewhere greater than 50 Gs -- and probably closer to 80 Gs. If a driver's ear accelerometer shows 50 Gs, IndyCar typically does follow-up examinations even if a driver doesn't show immediate symptoms of a concussion.
NASCAR drivers don't wear ear accelerometers, and adding them to the drivers' gear would require NASCAR approval because they count as an electronic recording device in the car. And NASCAR doesn't have traveling doctors like IndyCar, instead opting to have nurses travel with the circuit and rely on local physicians who meet certain criteria.
That adds to the perception, whether warranted or not, that NASCAR could be doing more in situations such as Earnhardt's.
Drivers, often known for toughness in this macho sport, typically race hurt unless a doctor tells them they can't -- and even then, they would try unless someone else (NASCAR or the team or their family) forbids them from stepping into the car.
Earnhardt told his team Tuesday that he might need a relief driver to help him get through the New Hampshire race because of the possible sinus infection, which he said he battled last weekend at Kentucky -- a week after the Daytona accident and a month after the Michigan wreck.
Hendrick Motorsports hasn't asked yet for any data from Earnhardt's crashes. Team general manager Doug Duchardt said he didn't notice any difference in Earnhardt during their Tuesday competition meeting.
"It was Mexican [food] day, so he was in a good mood," Duchardt said. "If you sat down and listened to him discuss the Kentucky race ... you would just think it's no different -- [it was] the same thing every week, the way he is."
While the policy is not specified in the NASCAR rulebook, Higdon said NASCAR drivers have an obligation to report any changes in medical history or diagnoses to the sanctioning body.
Now that Earnhardt has seen doctors and revealed a potential concussion diagnosis, NASCAR will require him to see a neurologist who has spent at least five years treating sports-related head injuries before he can be cleared to return. NASCAR requires drivers to undergo a type of neurological test called ImPACT once every two years, and that is typically used by neurosurgeons to determine whether a driver can compete.
The Immediate Post-Concussion Assessment and Cognitive Testing is not a pass/fail test. The 20-minute test measures a range of neurocognitive functions, including memory, reaction time, attention span and other cognitive skills. By undergoing a test that shows their baseline, the drivers can then go through the test again after a potential injury so doctors can observe any changes and determine if drivers have a concussion.
"There's never been that clarity from NASCAR or from the doctors on what they think is allowed to get back in the race car and what isn't," Busch said. "That's still something I'm still unknown of."
Earnhardt's decision will have competitive ramifications. He is 34 points up on the current Chase cutoff, where Trevor Bayne is the first driver currently on the outside looking in. Bayne has averaged 23.8 points per race this year.
Missing more than one race could make it tough for Earnhardt to make the Chase on points, especially with his recent struggles on the track. Alex Bowman replaces him this weekend, and Jeff Gordon, if necessary, will come out of retirement next week and substitute for Earnhardt.
"It's probably one of the toughest things to do. ... If I was in that position, it would be very tough for me, I would think," said Ryan Newman, who also is on the bubble to make the Chase for the Sprint Cup. "But I don't have the past he has to know the right move."