A traumatic brain injury is any blow to the head that disrupts the brains normal functions, even for a moment. The mildest traumatic brain injuries are concussions with no lasting effect. But at their most serious, traumatic brain injuries can leave their victims permanently disabled, unable to function without help. Victims may never be able to work again and need care for the rest of their lives. When brain injuries are caused by someone elses carelessness, victims and their families may sue that person to recover compensation for their losses.