Pericardial effusion two years after lung cancer surgery can be cancerous pericardial effusion, tuberculous pericardial effusion or infectious pericardial effusion, with different characteristics. 1. Cancer pericardial effusion, the amount of pericardial effusion is usually large, and the clinical manifestations such as dyspnea are more obvious, and the treatments are mainly anti-tumor treatment and extraction of pericardial effusion. 2. Tuberculous pericardial effusion, patients often have the history of tuberculosis and the symptoms of tuberculosis poisoning, such as low fever, night sweating (abnormal sweating after going to sleep, and the sweating stops after waking up). Because lung cancer leads to low immunity of the patient’s body and recurrence of tuberculosis. The amount of pericardial effusion is also higher and the color is mostly bloody. 3. Infectious pericardial effusion, including idiopathic pericardial effusion and purulent pericardial effusion. The former will not have obvious symptoms, and the amount of effusion will be less, but accompanied by obvious chest pain. The latter will have a slightly larger amount of fluid, but is often accompanied by a markedly high fever. It is recommended to consult a doctor in time to clarify the cause of the disease and follow the doctor’s instructions to standardize the treatment.