Whether pleural effusion occurs after lung nodule surgery can be determined by physical examination and imaging methods. 1. Physical examination: After surgery for pulmonary nodules, the main way to check whether there is pleural effusion is through thoracic palpation. When palpation is performed, the patient should palpate from the second intercostal space downward, and when a turbid or solid sound is heard, it indicates that there is pleural effusion in that intercostal space downward. 2. Imaging examination: the presence of pleural effusion after lung nodule surgery can also be confirmed by chest CT and other imaging means. The presence of pleural effusion will show parallel and invisible changes between the periphery of the lungs and the chest wall, and the shadows on CT will change accordingly when the patient’s position changes. The presence of pleural effusion can be determined by physical examination and imaging after surgery for pulmonary nodules, and it is recommended that the diagnosis be made under the supervision of a physician in conjunction with the appropriate symptoms.