Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Kidney Diseases ?
    ### Response:
    Your kidneys are two bean-shaped organs, each about the size of your fists. They are located near the middle of your back, just below the rib cage. Inside each kidney about a million tiny structures called nephrons filter blood. They remove waste products and extra water, which become urine.
    