Coughing from time to time does not necessarily mean lung cancer. Lung cancer mainly refers to occupying lesions in the lungs. For the occupying lesion, a puncture biopsy of the mass or fiberoptic bronchoscopy is done to obtain pathological tissue and see if there are cancer cells under the microscope. Then it is clear whether the lung cancer is adenocarcinoma of the lung, squamous lung cancer, or small cell lung cancer. The cause of cough can be bronchitis or chronic bronchitis, bacterial infection in the lung, fungal infection or foreign body, and bronchial asthma can all cause frequent coughing. Therefore, coughing from time to time may not necessarily be lung cancer, but for long-term chronic cough, CT examination of lung is needed to rule out whether it is combined with lung cancer.