Small nodules in the apical posterior segment of the upper lobe of the left lung can be temporarily observed, periodically reviewed, and surgically treated if necessary. The specific treatment needs to be combined with the specific situation of the patient. 1. If the diameter of the nodule <5mm solid nodule, it is recommended to follow up after 1 year, and if growth is found, it will be included in the high-risk nodule treatment, and no growth will be followed up annually. Non-solid nodules with a diameter between 5 mm and 15 mm and no obvious signs of malignancy on CT. Follow-up should be performed after 3 months to observe the growth characteristics, and if growth is detected, the nodule is included in the high-risk nodule management, and if there is no growth, the nodule will be followed up for 2 years. If the nodule grows significantly in the follow-up, the patient should be highly alert to the possibility of cancerous transformation of the nodule and should undergo surgical resection as early as possible, and the patient should be evaluated for contraindications to surgery before surgery. 2. Solid pulmonary nodules between 8 mm and 15 mm in diameter that are ≥15 mm in diameter or show malignant CT signs (lobulation, burr, pleural pulling, air-containing bronchiolar and vesicular signs, eccentric thick-walled cavities). Surgical treatment is preferred for those who are highly suspected of malignancy and are suitable for surgical treatment. It is recommended to seek prompt medical attention for the detection of lung nodules, and to follow the doctor’s instructions to complete the relevant examinations and treatments.