Traumatic brain injury is defined as damage to the brain resulting from external mechanical force such as rapid acceleration or deceleration impact blast waves or penetration by a projectile brain function is temporarily or permanently impaired and structural damage may or may not be detectable with current technology. Traumatic brain injury overview traumatic brain injury usually results from a violent blow or jolt to the head or body an object that goes symptoms traumatic brain injury can have wide ranging physical and psychological effects some signs or symptoms may causes traumatic brain injury is . Traumatic brain injury tbi a form of acquired brain injury occurs when a sudden trauma causes damage to the brain tbi can result when the head suddenly and violently hits an object or when an object pierces the skull and enters brain tissue symptoms of a tbi can be mild moderate or severe depending on the extent of the damage to the brain a person with a mild tbi may remain conscious or may experience a loss of consciousness for a few seconds or minutes other symptoms . Cdc defines a traumatic brain injury tbi as a disruption in the normal function of the brain that can be caused by a bump blow or jolt to the head or penetrating head injury everyone is at risk for a tbi especially children and older adults facts about tbi