What is a closed head injury?
A closed head injury is a trauma in which the brain is injured as a result of a blow to the head, or a sudden, violent motion that causes the brain to knock against the skull. A closed head injury is different from an open head injury, in that no object actually penetrates the brain. Closed head injuries can be diffuse, meaning that they affect cells and tissues throughout the brain; or focal, meaning that the damage occurs in one area. Closed head injuries can range from mild to severe.