Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Shock ?
    ### Response:
    Shock happens when not enough blood and oxygen can get to your organs and tissues. It causes very low blood pressure and may be life threatening. It often happens along with a serious injury.     There are several kinds of shock. Hypovolemic shock happens when you lose a lot of blood or fluids.
    