There are many conditions that can lead to solid nodules in the lower lobe of the lung, mainly including benign nodules, malignant nodules and nodules caused by pathogenic bacteria, and our treatment methods are different for different situations: 1. If the patient’s nodules are small with smooth edges, we consider them to be benign nodules and only need to review them regularly. 2. If the nodules are large, with unsmooth edges and burr signs, we consider them to be malignant nodules and need to If the patient has cough, sputum, fever and other symptoms, we consider the nodules caused by pathogenic bacteria, and need to take a targeted treatment according to the pathogenic bacteria and review after treatment.