When many lung cancer patients come to the clinic, they are found to have fluid in the chest cavity by chest X-ray or CT, so does it mean that patients with fluid in the chest cavity cannot be operated? This depends on the specific situation. Two kinds of cases should be treated differently, one is reactive, for example, because of long-term fever, malnutrition, hypoproteinemia, fluid accumulation in the chest cavity or even abdominal cavity, and may be accompanied by edema of both lower limbs. Or because the tumor blocked the bronchial tubes, there is atelectasis. Pleural fluid may appear. The second condition is the pleural fluid caused by tumor metastasis. In this case, because the tumor spreads in the chest cavity, there are large and small metastatic nodules on the lung surface and pleura on the rib surface. Generally, if fluid is found, most of the doctors will ask for ultrasound and then puncture and aspiration. On one hand, after aspiration, the patient’s symptoms will be improved because the compression of the lung will be improved after aspiration. On the other hand, it is to clarify the diagnosis, whether there is metastasis in the chest or not. The water is sent for laboratory tests, and if cancer cells are found inside, the diagnosis can be confirmed. In the two cases of last year mentioned above, the first one can be operated after treatment. In the second case, if the metastasis in the chest water is confirmed, there is no point to operate. Then there is no point to operate because metastasis of pleural fluid is stage 4 lung cancer, which may only last 6-12 months with or without surgery. In this case, surgery cannot prolong life, so there is no need to do surgery.