Early stage of lung cancer, some patients will have cough, which needs to be determined according to the location of tumor. Most of lung cancer patients do not have obvious symptoms in early stage, only some of them will have irritating dry cough, chest tightness, coughing up phlegm, etc. There are certain individual differences, which need to be analyzed according to the location of tumor growth, physical condition, etc. Moreover, it cannot be identified as lung cancer with a single cough symptom. For example, if lung cancer occurs in the bronchial area, because it will cause irritation to the airways, early patients will have repeated and persistent dry cough; however, if the lesion is located in the outer part of the lungs, there will be no symptoms such as coughing, which is difficult to be detected, and it needs a professional physical examination to be detected.