Categories of Traumatic Brain Injuries MILD Loss of consciousness for less than 30 minutes Alteration of consciousness for up to 24 hours Amnesia for less than or equal to one day Glasgow Coma score of 13-15 MODERATE Loss of consciousness for more than 30 minutes, but less than 24 hours Alteration of consciousness for more than 24 hours Amnesia for two or more days, but less than seven days Glasgow Coma score of 9-12 SEVERE Loss of consciousness for greater than 24 hours Alteration of consciousness for more than 24 hours Amnesia for seven or more days Glasgow Coma score of 3-8