Microscopic subpleural nodules in the left lower lung are nodular lesions less than 5 mm in size found in the left lower lung subpleural during a chest CT examination. If the nodule has a tendency to grow, or if the patient has cough, chest pain, hemoptysis and other symptoms, the patient should go to the hospital for enhanced CT, bronchoscopy and other examinations to further clarify the diagnosis and, if necessary, to perform If necessary, the nodules can be removed by surgical operation. Of course, if the nodule does not grow during the review, clinical observation can be continued.