Right lung middle lobe expansion insufficiency may be related to obstructive lung atelectasis such as inflammation, and compressive lung atelectasis such as tumor. 1. Obstructive lung atelectasis: If the lung atelectasis is due to obstructive factors, such as lung infection and inflammation can not be discharged in time and blocked, resulting in right lung middle lobe atelectasis; or due to foreign body aspiration, endobronchial tuberculosis and so on, resulting in right lung middle lobe atelectasis. 2. Compressive lung atelectasis: due to lung tumor, enlarged lymph nodes and other external compression, the bronchial lumen of the middle lobe of the right lung is narrowed, which affects the ventilation function of the middle lobe of the right lung, resulting in right lung middle lobe atelectasis; pleural effusion and pneumothorax caused by various reasons, which take up the volume of the pleural cavity, so that the corresponding lung tissues can not be sufficiently reexpanded and are compressed, resulting in right lung middle lobe atelectasis. It is recommended to go to the hospital in time.