Milled glass density foci in the upper lobe of the right lung refers to inflammatory or non-inflammatory exudates in the upper lobe of the right lung due to various etiological factors, which appear as milled glass-like changes in chest CT or chest radiography, and are commonly found in lung infections, lung tumors, and tuberculosis of the lung. 1. Lung infection: due to the infection of pathogenic bacteria such as bacteria and mycoplasma, a large amount of inflammatory exudate is produced, which accumulates in the lungs and forms foci, resulting in ground-glass-like changes in the lesion area of the upper lobe of the right lung, which is often accompanied by symptoms such as cough, sputum and fever. 2. Lung tumor: after a large number of tumor cells are damaged, ischemic necrosis leads to glassy changes in the lesion area of the upper lobe of the right lung, which is often accompanied by hemoptysis, weight loss, dyspnea and other symptoms. It should be noted that the superficiality and depth of the density foci have little relationship with the benign or malignant nature of the tumor, and the determination of the benign or malignant nature of the tumor needs to be clarified through pathological examination. 3. Lung tuberculosis: mostly caused by Mycobacterium tuberculosis infection, the lesion involves the upper lobe of the right lung, and there is glassy change in the lesion area of the upper lobe of the right lung, which is often accompanied by symptoms such as low fever and night sweating (abnormal sweating after going to sleep, but sweating stops after waking up), etc. On examination, there is glassy change in the lesion area of the upper lobe of the right lung. Examination of the right upper lobe of the lungs grinding glass density foci, may also be other causes, it is recommended to timely hospital consultation, identify the cause of the disease, and then follow the doctor’s instructions for treatment, in order to prevent delays in the condition.