Lung nodules are considered proliferative foci, the full name of proliferative foci is pulmonary fibroproliferative foci, which are caused by inflammatory infections, tuberculosis, chronic bronchitis, silicosis, and other causes. Repeated inflammatory infections stimulate fibrous striated foci visible under CT. Generally, pulmonary nodular proliferative foci are considered benign and do not have lung function and rarely appear to be cancerous. Patients are advised to pay attention to their respiratory system. If cough, sputum and dyspnea occur in general and last for a relatively long period of time, they need to go to the hospital as soon as possible to find out the cause, and at the same time, patients should strengthen their resistance and participate in more outdoor exercises in general.