The presence of ground glass shadows in the lungs is generally considered to be an infectious disease of the lower respiratory tract, most often due to exogenous allergic alveolitis, pulmonary infections, and also due to ground glass changes caused by pulmonary edema. If the ground glass is nodular, a preliminary determination of whether the disease is benign or malignant needs to be made based on the size and nature of the nodule. If the pulmonary ground glass nodule is below 5mm, it is mostly benign, 6-8mm needs close follow-up, if it is larger than 8mm with lobar and burr signs, it needs to be highly alert to the tendency of ground glass to become cancerous. For pulmonary ground glass, it depends on the size and area of the ground glass as well as its distribution. If the ground glass is distributed in the upper lobes of both lungs, a high alert for tuberculosis is needed. If the ground glass is in the lower part of both lungs, one needs to be alert for alveolar stasis, pulmonary edema, and interstitial fibrosis with infection in both lower lungs. In conclusion, the differential diagnosis of ground glass is mostly based on high-resolution CT of the chest and is commonly associated with infections, tuberculosis, heart failure, and interstitial lung changes.