Ground glass shadows in the lungs may be due to lung infection, pulmonary edema, alveolar hemorrhage, and neoplastic disease. 1. Lung infection: it is a common cause of ground-glass shadow in the lungs. Pneumonia is a serious infection of the lungs, which may be caused by viruses, bacteria or fungi. Symptoms include coughing, coughing up yellow or white sticky sputum, extreme fatigue, fever, and loss of appetite. 2. Pulmonary edema: is the result of fluid collecting in the air spaces of the lungs and may be caused by a variety of conditions, such as heart failure and altitude sickness. It may be accompanied by hemoptysis, shortness of breath, and restlessness. 3. Alveolar hemorrhage: Alveolar hemorrhage occurs when blood vessels in the lungs are damaged and cause bleeding and can be caused by a variety of conditions such as autoimmune disorders, vasculitis, and bleeding disorders. Symptoms vary widely and may include hemoptysis and dyspnea. 4. Tumor disease: Grinding glass shadow in the lungs may also indicate cancer. In the early stage of lung cancer, there may be no obvious symptoms, and with the development of the disease, there will be persistent coughing, shortness of breath, chest and back pain. If patients have ground glass shadow in examination, it is recommended to have further examination in time, and actively treat the disease after clarifying the cause.