Pleural effusion has different causes and different treatment methods. After the diagnosis of the cause is clear, treatment should be carried out for different causes. If necessary to reduce symptoms, a certain amount of pleural fluid can be extracted to reduce the patient’s symptoms of inspiratory distress. 1. tuberculous pleural effusion Most patients are treated satisfactorily with anti-tuberculosis drugs. A small amount of pleural fluid generally does not need to be extracted or only diagnostic puncture. Thoracentesis not only helps to diagnose, and can relieve the lungs and heart, vascular pressure, improve whistling, prevent fibrin deposition and pleural thickening, so that lung function from damage. After aspiration, it can reduce the symptoms of toxicity and make the patient’s body temperature drop. A large amount of pleural fluid can be pumped 2 to 3 times a week until the pleural fluid is completely absorbed. The amount of fluid should not exceed 1000 ml each time. Too fast or too much fluid can cause a sudden drop in chest pressure, resulting in pulmonary edema or circulatory disorders, manifested as severe cough, shortness of breath, coughing up large amounts of foamy sputum, wet rales in both lungs, a drop in PaO2, and an X-ray chest radiograph showing pulmonary edema signs. At this time, oxygen should be administered immediately, glucocorticoids and diuretics should be applied as appropriate, water intake should be controlled, and the condition and acid-base balance should be monitored closely. If “pleural reaction” occurs during fluid extraction, which is characterized by dizziness, cold sweat, palpitation, pallor, thin pulse and cold extremities, fluid extraction should be stopped immediately, the patient should be made to lie down, and if necessary, 0.1% epinephrine 0.5ml should be injected subcutaneously, and the condition should be closely observed to pay attention to blood pressure and prevent shock. In general, it is not necessary to inject drugs into the chest cavity after pumping chest fluid. Glucocorticoids can reduce the metabolic and inflammatory reactions of the organism, improve the toxic symptoms, accelerate the absorption of pleural fluid, and reduce the sequelae such as pleural adhesions or pleural thickening. However, there are certain adverse effects or lead to the spread of tuberculosis, so the indications should be carefully controlled. For acute tuberculous exudative pleurisy with severe systemic toxicity and more pleural fluid, glucocorticoids, usually prednisone or prednisolone, can be added along with anti-tuberculosis drug therapy. When the patient’s body temperature is normal, the symptoms of systemic toxicity are reduced or subside, and the pleural fluid is obviously reduced, the dosage should be gradually reduced or even discontinued. The speed of discontinuation should not be too fast, otherwise it is easy to rebound phenomenon, generally the course of treatment 4-6 weeks. 2. Pneumonia-related pleural effusion and abscess chest The treatment principle is to control the infection, drain the pleural effusion, as well as promote lung reopening and restore lung function. For the pathogenic bacteria of pneumothorax, effective antibacterial drugs should be applied as early as possible, and systemic and intrathoracic drugs should be administered. Drainage is the most basic treatment for abscess chest, which can be repeatedly pumped or closed drainage. The thoracic cavity can be repeatedly flushed with 2% sodium bicarbonate or saline, and then an appropriate amount of antibiotics and streptokinase can be injected to make the pus dilute and facilitate drainage. In a few cases of abscess chest, drainage tubes can be implanted between the ribs and connected to water seal bottles to export the pleural fluid. For those with bronchopleural fistula, it is not advisable to flush the chest cavity to avoid bacterial dissemination. Patients with chronic abscess chest with symptoms such as pleural thickening, thoracic collapse, chronic wasting and pestle finger (toe) should be considered for treatment such as surgical pleurodesis. In addition, general supportive treatment is also quite important, and high energy, high protein and vitamin-containing food should be given. Correction of water-electrolyte disorders and maintenance of acid-base balance, if necessary, a small number of blood transfusions can be given. 3. Malignant pleural effusion Therapeutic thoracentesis and pleural fixation are the common methods for treating malignant pleural effusion. Due to the rapid growth and persistence of pleural effusion, patients often have severe aspiration difficulties due to the compression of large amounts of effusion, which may even lead to death. Therefore, repeated thoracentesis and aspiration are required for such patients. However, repeated aspiration can cause too much protein loss (1 liter of pleural fluid contains 40 grams of protein), so the treatment is very difficult and the effect is not satisfactory. For this reason, correct diagnosis of malignant tumor and tissue type and timely reasonable and effective treatment are important to relieve symptoms, reduce pain, improve survival quality and prolong life. Systemic chemotherapy has certain efficacy for pleural effusion caused by some small cell lung cancers. Local radiation therapy is feasible for those with metastasis in mediastinal lymph nodes. Intrathoracic injection of antitumor drugs including adriamycin, cisplatin, fluorouracil, mitomycin, nitrocarbamazine, bleomycin, etc., after aspiration of pleural fluid is a common treatment method. This helps to kill tumor cells, slow down the production of pleural fluid, and can cause pleural adhesions. Intrathoracic injection of biological immunomodulators is a more successful method to explore the treatment of malignant pleural effusion in recent years, such as Corynebacterium shortum vaccine (CP), IL-2, interferon beta, interferon gamma, lymphokine-activated killer cells (LAK cells), and tumor-infiltrating lymphocytes (TIL), which can inhibit malignant tumor cells, enhance local infiltration and activity of lymphocytes, and cause pleural adhesions. To occlude the pleural cavity, pleural adhesives such as tetracycline, erythromycin and talc can be injected after the drainage of pleural fluid by thoracic cannula to cause adhesion of two layers of pleura to avoid the re-formation of pleural fluid. If a small amount of lidocaine and dexamethasone is injected at the same time, it can reduce pain and fever and other adverse reactions. 4. Leaky pleural effusion For leaking pleural effusion, the main treatment is to deal with the primary disease. When the amount of effusion causes obvious clinical symptoms or when the treatment of the primary disease is not effective, the symptoms can be relieved by methods such as closed chest drainage.