Pure ground glass nodules in the lungs may be a sign of diseases such as pneumonia, atypical neoplastic hyperplasia, and malignant tumors of the lungs. 1. Pneumonia: it is an inflammatory disease that mainly occurs in lung tissues. When lung tissues are damaged and there is alveolar formation, the presence of ground-glass nodules will be found through examination. 2. Atypical neoplastic hyperplasia: it is a pre-cancerous lesion of lung, which is a single-row non-invasive atypical confined hyperplasia of alveolar wall epithelium, which is not cancerous but has the risk of being cancerous, and it is usually caused by chronic inflammation stimulation for a long period of time. 3. Lung malignant tumor: pure ground-glass nodules in lungs are usually early stage lesions without metastasis, with a diameter of less than 1cm, and the possibility of carcinoma in situ without outward infiltrative growth is high. Pure ground glass nodules in lungs may be benign or malignant, and it is necessary to do pathological biopsy to analyze the nature of the tumor, and then carry out targeted treatment, specific should consult professional physicians.