Most of the small glass foci in the right upper lung are inflammation and edema caused by lung infection, tuberculosis or rheumatoid immune disease in the lung, and a very small part of them are tumor lesions in the lung. 1. Most of the small glass foci in the right upper lung are inflammation and edema, usually with unclear boundaries, often caused by lung infection, tuberculosis or rheumatic immune diseases, and can be absorbed or even absorbed by themselves after anti-infection, anti-tuberculosis or immunopathogenic treatment. 2. Small glass foci in the right upper lung are rarely caused by lung tumors, including primary lung cancer and metastatic cancer, which should be further determined after physical examination and other tests, such as high-resolution chest CT, PET-CT and tumor markers. It is recommended to go to the hospital for further consultation and diagnosis to clarify the specific cause of the disease and avoid delaying the condition.