A Traumatic Brain Injury (TBI) is defined as a blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain. Not all blows or jolts to the head result in a TBI. The severity of a TBI may range from mild, i.e., a brief change in mental status or consciousness to severe, i.e., an extended period of unconsciousness or amnesia after the injury1.
References:
1Centers for Disease Control and Prevention, Injury Center