Traumatic brain injury is a head injury that results from sudden trauma which causes brain cell destruction or degeneration. Types of head injury include contusions or bruising of the brain and intracranial hemorrhage or heavy bleeding in the skull. This could be caused by a closed head injury such as being hit on the head with a blunt object or penetrating head injury or when an object penetrates through the skull damaging brain tissues.

Most head injury cases with people under 75 years old are caused by vehicular accidents, while a majority of cases involving people over 75 years old are caused by falls. Such injuries can also be caused by other conditions such as a stroke, meningitis or anoxia. The brain