A small amount of pleural effusion exists in the body itself. For pathologic pleural effusions, treatment of the primary cause of the pleural effusion is the quicker way to heal and cure the pleural effusion. A small amount of pleural effusion can be cured on its own if the primary disease is treated promptly and effectively. If the primary disease such as tuberculosis or infection is well controlled, a small amount of pleural effusion can be absorbed and achieve clinical self-healing. However, if the primary disease, such as malignant tumor, is not effectively and timely controlled, pleural effusion not only can not be self-healing, but will become more and more. Clinically, the treatment of pleural effusion needs to target the cause of pleural effusion. For example, anti-tuberculosis drugs such as rifampicin should be given to patients with infections and treated according to the course of treatment. If the pleural effusion is caused by tumor, surgical treatment, radiotherapy and chemotherapy should be chosen according to the stage of the tumor and the nature of the tumor. If the pleural effusion is caused by bacterial infection, anti-infection treatment is needed. When the pleural effusion in the patient’s body is large, these patients need closed drainage treatment method.