Lung speckled shadow refers to the presence of speckled shadow in the lungs as shown in the imaging examination, which is mostly seen in inhalation of dust, lung infection and tuberculosis. 1. Inhalation of dust: Some workers who have long-term exposure to dust, such as coal miners, chefs, chemical workers, etc., may cause localized lung speckled shadow when doing imaging examination due to long-term exposure to large amount of dust, and silicosis may be formed if it develops further; 2. Lung infection: it may be caused by infectious factors, the causative agent may be viruses, bacteria, mycoplasma, etc., due to the local inflammatory reaction, thus forming speckled shadows. 3. Tuberculosis: Generally, it is the traces left after the patient has been infected with tuberculosis and cured after treatment. Lung speckled shadow may also be caused by other diseases, such as lung cancer, generally after getting the examination report, it should be promptly submitted to the doctor for diagnosis, and cooperate with the doctor to take treatment.