A solid pulmonary nodule in 5mm is clinically considered a small nodule. If the patient does not have any clinical symptoms and has normal immune function, it is recommended to review it periodically, after six months or one year, to dynamically observe any significant changes. If there are no significant changes, the nodule is clinically considered benign and no specific treatment is required. If a patient has a 5mm nodule with irregular margins and symptoms such as cough, sputum, coughing up blood, weakness, and weight loss, it is not excluded as a malignant nodule and requires further improvement of the tumor series, lung nodule puncture biopsy, bronchoscopy and other related examinations to further confirm whether it is a malignant nodule. If the nodule is malignant, surgery or radiotherapy, chemotherapy, immunotherapy with targeted cellular drugs, etc. will be required.