Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) hypokalemic periodic paralysis ?
    ### Response:
    Hypokalemic periodic paralysis is a condition that causes episodes of extreme muscle weakness typically beginning in childhood or adolescence. Most often, these episodes involve a temporary inability to move muscles in the arms and legs. Attacks cause severe weakness or paralysis that usually lasts from hours to days.
    