Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Head Injuries ?
    ### Response:
    Chances are you've bumped your head before. Usually, the injury is minor because your skull is hard and it protects your brain. But other head injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury.    Head injuries can be open or closed.
    