Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Anemia ?
    ### Response:
    If you have anemia, your blood does not carry enough oxygen to the rest of your body. The most common cause of anemia is not having enough iron. Your body needs iron to make hemoglobin. Hemoglobin is an iron-rich protein that gives the red color to blood. It carries oxygen from the lungs to the rest of the body.
    