Professional football players often suffer major head injuries, leading to recent studies that warn of the long-term effects and increased risk of dementia. While concussions are the most prevalent and researched injury, new studies show that players who do not sustain concussions are still at risk for long-term consequences due simply to the high-impact nature of the sport. The Cleveland Clinic and University of Rochester conducted a study on 67 college football players who did not receive concussions during a game, but who were then given blood tests and were studied for signs of similar concussive symptoms. The blood tests looked for a protein called S100B, which is found in patients who suffer traumatic brain injuries as it indicates damage to the blood-brain barrier. Some of the players tested showed indications of S100B in their blood, even without sustaining an actual concussion. Researchers were unsure what made the difference in the types, locations, and levels of force inflicted by particular hits during the game that caused S100B to be released in some players but not in others. MRIs of the affected players showed changes consistent with traditional signs of brain damage despite a lack of an actual concussion. These “subconcussions” appear to be just as dangerous as more severe head injuries, but have been often overlooked and are becoming a silent and potentially deadly danger.