Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Varicose Veins ?
    ### Response:
    Varicose veins are swollen, twisted veins that you can see just under the skin. They usually occur in the legs, but also can form in other parts of the body. Hemorrhoids are a type of varicose vein.    Your veins have one-way valves that help keep blood flowing toward your heart.
    