Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Lung Diseases ?
    ### Response:
    When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a normal day, you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in the U.
    