Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Asthma in Children ?
    ### Response:
    Asthma is a chronic disease that affects your airways. Your airways are tubes that carry air in and out of your lungs. If you have asthma, the inside walls of your airways become sore and swollen.    In the United States, about 20 million people have asthma.
    