The incidence of lung cancer is obviously increasing, and its early symptoms are not obvious, so the early diagnosis of lung cancer is difficult. In recent years, some risk factors and early signals related to lung cancer have been found: 1. cough: the first symptom of 60%-80% of lung cancer patients is cough, mostly dry cough without sputum. 2.Blood sputum: It is manifested as intermittent sputum with blood in it. 3. Chest pain: intermittent vague or dull pain that is not fixed, and the vague pain may also travel to the neck, shoulder, back or upper abdomen. 4.Fever: Fever is the first symptom of a small number of lung cancer patients. People are often least likely to associate it with lung cancer, thus resulting in missed diagnosis. The above symptoms should be checked in hospital immediately. For men who have a history of smoking for many years, more than 1 pack per day, those whose living environment is heavily polluted by the atmosphere, those who have a history of exposure to asbestos, arsenic, chromium, coal tar and radioactive substances, even if they do not have the above symptoms, they should have a chest X-ray once every six months, and those who have the conditions should preferably have a CT examination, which can often detect early lung masses earlier. After the lung mass is found, a fiberoptic bronchoscopy, or lung puncture, and pathological examination can be done to make a clear diagnosis.