Traumatic brain injury, which is also known as a brain injury or head injury, occurs when a blow or jolt to the head results in damage to the brain. And a traumatic brain injury can range in severity from mild to severe. A mild traumatic brain injury occurs when a person has a brief change in their mental status or a loss of consciousness. It’s most commonly known as a concussion and often goes undiagnosed and therefore the person who suffers that type of loss doesn’t usually get the benefits that they need. Severe traumatic brain injury involves a loss of consciousness for hours or days or weeks and can result in permanent disability.