If the patient’s pleural effusion is red, it is not necessarily a tumor, but it may be that when the patient undergoes puncture, the peripheral blood vessels are damaged, then the blood vessels rupture and the blood flows into the chest cavity, which may be mixed with the pleural effusion, and so the pleural effusion is red when it is withdrawn. In addition, patients with tuberculosis may also have red bloody pleural effusion, we can do a tuberculin test to determine whether the patient is a patient with tuberculosis, in order to distinguish it from patients with tumors. So when a patient has a red pleural effusion, it is not necessarily a tumor. We need to make a comprehensive judgment on the basis of puncture biopsy, chest CT and other imaging results, and exfoliative cytology of pleural effusion. If the patient has red pleural effusion, don’t be overly nervous, and should actively cooperate with the physician’s treatment and maintain a good state of mind.