Multiple pulmonary nodules and solitary nodules require attention other than the number of nodules. Multiple pulmonary nodules are most often seen in infectious diseases of both lungs, such as chronic bronchitis, chronic obstructive pulmonary disease, bronchiectasis, pulmonary fibrosis, and long-term smoking and exposure to dust, including masons, coal miners, cooks, hairdressers, tailors, etc. Repeated inhalation of odors and dust can easily lead to the development of multiple nodules in both lungs. Single nodules need further clarification of the size and nature of the nodules. If the nodules are ground glass with some solid nodular changes, both need to be judged as early benign and malignant disease based on the size of the nodules. Multiple pulmonary nodules can also be seen in metastatic lung cancer in both lungs, which need to further suggest the diagnosis based on chest imaging, especially high-resolution CT of the chest. Fiberoptic bronchoscopy, microscopic alveolar lavage fluid examination is given if necessary to understand whether it is infection, tuberculosis, tumor, etc. If the lung solitary nodule is large, enhanced CT of the chest as well as percutaneous lung puncture examination need to be given to rule out the possibility of early lung cancer as early as possible.