Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Pulmonary Hypertension ?
    ### Response:
    Pulmonary hypertension (PH) is high blood pressure in the arteries to your lungs. It is a serious condition. If you have it, the blood vessels that carry blood from your heart to your lungs become hard and narrow. Your heart has to work harder to pump the blood through.
    