Pleural effusions are classified into bacterial, tuberculous and tumorigenic according to their nature, and into small amount of pleural effusion, medium amount of pleural effusion and large amount of pleural effusion according to the amount of fluid. Different pleural effusion types are treated in different ways, and the specific treatments are as follows: 1. Small amount of pleural effusion: can be conservatively treated without closed chest drainage or thoracentesis; 2. Medium amount and large amount of pleural effusion: manifesting as a series of clinical symptoms such as chest tightness, shortness of breath and dyspnea, closed chest drainage or thoracentesis can be used to alleviate and relieve clinical symptoms; 3. Inflammatory pleural effusion: antibiotics are used to reduce and inhibit the inflammatory reaction and reduce the amount of pleural effusion; 4, cancerous pleural effusion: closed thoracic drainage and intrathoracic injection of drugs to close the pleural cavity are commonly used to reduce the production of effusion.