4 mm milled glass nodules, in general, it does not matter, need to be regularly reviewed, 4 mm milled glass nodules may be due to infection, can be reviewed two weeks after the anti-infection, or dynamic follow-up observation, but can not completely exclude the possibility of malignancy. Lung infection leads to inflammatory exudate proliferation in the lung, local inflammation or granulation tissue parcel, nodules caused by infection are seen in bacterial infection and viral infection, bacterial infection is given antibiotic treatment, such as ceftriaxone, piracillin, etc.; viral infection is given antiviral treatment, such as oseltamivir, ribavirin, etc., generally, after the sensitive antibiotics anti-infective treatment or standardized antiviral treatment, the nodule can be reduced significantly or disappear. The nodules will usually shrink or disappear after sensitive antibiotic treatment or standardized antiviral treatment. The nodules should be followed up dynamically, and the chest CT should be repeated periodically to see if the nodules tend to get bigger or increase in size. If there is a clear tendency for the nodules to increase in size, surgical intervention should be performed as soon as possible; if there is no change in the nodules, dynamic follow-up can be continued. If any of the above situations, it is recommended to go to the hospital as soon as possible to avoid delaying the condition.