Pulmonary Frosted Glass Nodule refers to the presence of a cloudy, thin shadow with mildly increased density resembling the texture of frosted glass on chest CT. They may be malignant tumors or benign lesions in the lungs, or inflammation, etc. The clinical manifestations are related to the etiology. 1. Malignant tumor: if the ground glass nodule is larger than 8mm, and at the same time the border is not clear, accompanied by burr sign, lobulation, etc., consider the possibility of malignant lung tumor. Clinical manifestations may have no special symptoms, but cough, sputum, blood in sputum, chest tightness, wheezing and other symptoms are common after the disease develops to a certain stage. 2. Benign tumors: Generally speaking, if the ground-glass nodules in the lungs are less than 8mm, with clear boundaries, and the nodules are stable in the follow-up examinations, they are mostly considered as benign tumors. Generally, there are no special symptoms, and the symptoms of chest tightness, chest pain and shortness of breath may occur. 3. Inflammatory lesions: they can be caused by limited bacterial infection, viral infection, fungal infection, allergy, etc. CT images mostly show multiple foci with unclear borders. Most of them have typical symptoms such as fever, cough and sputum, pulse rate, shortness of breath, and wet rales can be heard on lung auscultation. If nodules are detected in the lungs, it is necessary to seek medical treatment as soon as possible to avoid delaying the condition.