Head injury is trauma to the SCALP, SKULL, and/or BRAIN.

Scalp injuries may be superficial or associated with an underlying skull and/or brain injury.

Traumatic brain injury (or TBI) may result from either closed or open head injuries.

Closed head injuries, where the skull is not broken, result in TBI; this type of head injury may not be obvious and findings may be very subtle.

In open head injuries, the scalp and skull are broken resulting in a penetrating TBI; these head injuries are typically more obvious.