Normal people usually do not have nodules in their lungs, and if nodules are present, the cause needs to be clarified, such as infection, lung cancer, and environmental factors. 1. Infection: Bacterial, viral, tuberculosis and other infections can lead to the occurrence of lung nodules. 2. Lung tumors. (1) Benign tumors: benign tumors of the lungs, such as pulmonary fibroma, etc. can manifest as lung nodules, and follow-up or surgical treatment can be chosen according to the specific conditions of the tumors. (2) Malignant tumors: i.e. lung cancer, which can also manifest as lung nodules, surgical treatment or conservative treatment, such as radiotherapy and target drugs, can be chosen according to the specific conditions of patients. (3) Environmental factors: long-term exposure to asbestos, vinyl chloride and other environments, these substances are inhaled into the lungs to produce a reaction and form lung nodules through wrapping and mechanization. Normal people usually do not have nodules in the lungs. Patients with nodules in the lungs should go to regular hospitals, cooperate with doctors to complete relevant examinations, clarify the causes and deal with them actively.