Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Atherosclerosis ?
    ### Response:
    Atherosclerosis is a disease in which plaque builds up inside your arteries. Plaque is a sticky substance made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. That limits the flow of oxygen-rich blood to your body.
    