The seriousness of a 4-mm ground-glass nodule is determined by the condition of the nodule. If the nodule remains unchanged or disappears during the review, it is not serious; if the nodule continues to increase in size or localized solid changes during the review, it is serious. 1. If the ground-glass nodule is relatively small, and if it disappears or remains unchanged during the review process, it is basically a benign lesion and is not serious in itself. 2. If there are ground-glass nodules that continue to increase in size or change in appearance during the review process, there is a possibility of malignant lesions, and the corresponding condition is a more serious one. The appearance of grinding glass nodule enlargement needs timely medical observation, if necessary, through the puncture to take tissue for pathological diagnosis, to determine the condition and then do standardized treatment.