Pleural effusion, you should find out what is the amount of pleural effusion. If it is a small amount of pleural effusion, a small amount of pleural fluid can be extracted for biochemical and routine pleural fluid examination to clarify the cause of the pleural effusion, and then targeted treatment can be performed for the cause. If the amount of pleural effusion is large, reaching a moderate amount of effusion or a large amount of effusion, thoracentesis and aspiration or closed drainage should be performed for treatment. Thoracentesis aspiration should not exceed 600 ml for the first time, otherwise it is easy to develop diplopia pulmonary edema, which can be life-threatening in serious cases. The same is true for closed chest drainage, which should not exceed 600 ml for the first time.