Early stage of lung cancer may have no obvious symptoms, or there may be cough, sputum, blood in sputum, chest tightness, chest pain and other symptoms. 1. Cough and sputum: it is a common symptom in early stage of lung cancer. Tumor stimulates bronchial tube, which can be manifested as dry cough, or sputum due to stimulation of bronchial mucous membrane to secrete mucus. 2. Blood in sputum: it indicates that there is blood vessel rupture, which can be the blood vessel within the tumor or the blood vessel of the bronchus infringed by the tumor. Blood in sputum is manifested when the bleeding volume is small, and hemoptysis is manifested when the bleeding volume is large. 3. Chest tightness and chest pain: when the tumor of central lung cancer is located in the main bronchus, it can lead to obstructive ventilation dysfunction, chest tightness and chest swelling and pain. Peripheral lung cancer can cause dull chest pain when it invades the pleura. When lung cancer occurs, it must be treated as early as possible, which can effectively improve the five-year survival rate, and go to the hospital in time to avoid delaying the condition.