Abstract
In brief: Cerebral concussion occurs frequently in contact sports; more than 250,000 concussions occur annually in football alone. Definitions and classifications of severity of concussion vary, which makes evaluation of data extremely difficult. By combining elements of various definitions, the author has developed a practical, on-the-field grading scheme for identifying concussion in contact sports (grade 1: mild, with no loss of consciousness; grade 2: moderate, with less than five minutes of unconsciousness or more than 30 minutes of posttraumatic amnesia; grade 3: severe, with five or more minutes of unconsciousness or 24 or more hours of posttraumatic amnesia). Also discussed are management of concussion and guidelines for determining when an athlete may safely return to play.