Lung cancer is a malignant tumor of the lungs. With the development of the disease, it will cause a series of symptoms, mainly including cough, coughing up blood and chest pain. 1. Cough: the corresponding symptom is mainly caused by the stimulation of trachea and bronchial tubes due to the enlargement of tumor, which is mainly manifested as the symptom of dry cough. 2. Coughing up blood: it is closely related to bleeding caused by invasion of peripheral blood vessels or rupture of blood vessels after tumor enlargement. 3. Chest pain: chest pain is usually related to pleural irritation, which is caused by the invasion and destruction of surrounding tissues after tumor enlargement. In the advanced stage of some lung cancers, it may also cause nerve compression and lead to abnormal nerve function, or affect blood circulation and cause local edema. After the discovery of lung cancer, one should be hospitalized as early as possible, and under the guidance of doctors, carry out standard treatment to strive for a good therapeutic effect.