How long a lung cancer patient can live after coughing up blood is mainly related to the specific stage of lung cancer, the amount of coughing up blood and the individual condition of the patient, which needs to be evaluated comprehensively. Coughing up blood is a common clinical symptom of lung cancer. If a patient coughs up blood in a small amount, it indicates that the tumor cells have destroyed the capillaries in the lung and the phenomenon of blood in sputum occurs. If the patient coughs up a large amount of blood, such as coughing up more than 100ml of blood at a time, it indicates that the tumor has invaded large blood vessels, which is mostly in the middle and late stage, and the survival of the patient will be greatly affected. In early stage patients, after complete removal of tumor by surgery with chemotherapy, the survival period is generally more than 5 years, and some patients can reach more than 10 years. The 5-year survival rate of advanced stage patients is generally less than 10%, and the survival time is generally not more than 2 years. After coughing up blood in lung cancer patients, it is recommended to promptly clarify the bleeding site and carry out symptomatic treatment. In addition, patients should ensure sufficient sleep and improve their immunity, which can help prolong the survival period.