Ground glass in imaging refers to ground glass nodules or ground glass shadows, which is a description of the morphology of lung nodules on imaging and can be seen in a variety of diseases. 1. A sheet-like shadow that protrudes from normal tissue on imaging. If a patient undergoes a chest CT and finds a slightly denser, round-like, cloudy shadow on the lungs that is more similar to the frosted glass of life and is less than 3 cm in diameter, it is called a frosted glass nodule. 2. Frosted glass shadow in the lungs: it is mostly seen in interstitial pneumonia, including the interstitial pneumonia changes in both lungs caused by AIDS. Idiopathic pulmonary fibrosis in the alveolitis stage, also prone to bilateral lung glassy changes. 3. Pulmonary ground-glass nodules: it is necessary to make a comprehensive judgment according to the size and nature of the nodules. If the size of the nodule is less than 5mm, it is mostly benign and chronic inflammation, and no special treatment can be given if there is no clinical symptom. Chest CT can be performed once a year. If the lung ground-glass nodule is between 6 and 8 mm, or even larger than 8 mm, with short burrs and lobular shape, it is necessary to be alert to the possibility of early lung cancer in this nodule. Ground glass nodules in the lungs can be seen in a variety of diseases, such as pneumonia and other inflammatory diseases of the lungs, tuberculosis, lung tumors and so on. It is recommended to improve other examinations according to the signs and clinical manifestations to make a clear diagnosis and take targeted therapeutic measures.