There may be no symptoms in the early stages of interstitial lung disease, but there may be mild shortness of breath or shortness of breath after some activities, and sometimes a little cough, but this does not indicate the severity of the disease. Because interstitial lung disease is not particularly effective in treatment at this time, and it is a disease that continues to develop. Although there is no bacterial or pathogenic infection, it is easy to combine pathogenic infections during the course of the disease, and once infected, the symptoms and prognosis are worse than in patients without normal interstitial lung disease. Therefore, interstitial lung disease needs to be treated actively even if there are no symptoms in the early stage, as long as the disease is detected on CT imaging, but the priority of treatment can be determined by pulmonary function evaluation.