Blood in sputum for 5 to 6 years is not necessarily lung cancer. Blood in sputum is not a unique clinical manifestation of lung cancer, as many respiratory diseases have blood in sputum clinical manifestations, such as bronchodilatation, chronic bronchitis and lung abscess, etc. It is necessary for patients to go to the hospital for further relevant examinations, such as chest CT examination. If it is lung cancer, chest CT often suggests that the border around lung lesion is not clear and burr-like shadow appears, and bronchoscopy can be used to take pathological biopsy to confirm the diagnosis. If it is diagnosed to be lung cancer, it is necessary to carry out lung cancer tumor resection surgery, and according to the situation of radiotherapy treatment after surgery. Therefore, it is necessary for patients to go to the hospital for further examination and actively cooperate with doctors after finding out the cause of lung cancer, and avoid carelessness so as not to delay the treatment and miss the best time for treatment.