Multiple small nodules in both lungs refers to the discovery of nodules of different sizes on chest CT, which can be determined according to one’s own condition, generally may be related to lung infection, long-term smoking, exposure to dust and other factors, but there is also the possibility of malignant tumors. 1. Lung infection: it is due to chronic inflammation caused by bacterial and viral infections in the lungs, with mechanization, fibrous encapsulation and thus the formation of inflammatory nodules, local granulation tissue proliferation, which are shown as nodular lesions on CT. 2. Long-term smoking: long-term smoking, the chemicals in tobacco will destroy the villi in the lungs, stimulate the lung tissues, induce inflammatory reaction, thus appearing polyps, manifested in the form of nodules, in order to prevent the further deterioration of lung nodules, become malignant tumors, life should quit smoking. 3. Exposure to dust: When engaging in dusty work, due to the large particles of dust and strong irritation, long-term inhalation will lead to nodules in the lungs or cause infection, usually manifested as coughing, coughing up sputum and other symptoms, you can wear masks at work for good protection. If there are nodules in the lungs, regular review should be conducted under the guidance of a doctor to exclude the possibility of malignant tumors.