Concussion research has demonstrated that significant brain injury may still be present even though you may feel 'back to normal'. You are at a high risk of a more serious brain injury, as a result of a secondary concussion, during this time because the brain has not fully recovered from the original injury. Although you 'feel better', impairment in cognitive and neurophysiological function may still exist. This is why getting a baseline test is so important, because it will more accurately determine whether the brain has 'healed'.