A 5mm milled glass nodule is not serious if it is an inflammatory lesion, and more serious if it is caused by lung cancer. Lung nodules are focal round-like shadows with lesions less than or equal to 3cm in chest CT, and when the nodules appear as cloudy and dense shadows, they are called ground glass nodules. Frosted glass nodules may be caused by inflammatory lesions in the lungs caused by bacteria, viruses, etc., and may also be caused by bronchopulmonary cancer. Generally, the larger the ground-glass nodule, the higher the risk of malignancy. Ground-glass nodules smaller than 5mm are mostly benign, while ground-glass nodules larger than 8mm have a 20% or greater chance of being malignant. Generally, 5mm ground-glass nodules can be left untreated for the time being, with regular checkups, and puncture biopsy or surgical treatment can be considered if there are changes in the size and shape of the nodule. If you find ground glass nodules, it is recommended that you consult a doctor in time to find out the cause of the disease and treat it actively.