Dry cough cannot be determined as cancer, because there are many benign diseases that can manifest dry cough, such as pharyngitis, tonsillitis, upper respiratory tract infection and bronchitis. However, some lung cancer patients show dry cough, such as tumor located near the lung door, which is called central lung cancer, and the long location is in the lung door or in the large airway, which happens to stimulate the airway and cause coughing. Therefore, it is necessary to do further examinations, such as chest X-ray and CT, combined with other corresponding symptoms, to improve the relevant examinations, so as to clarify whether the cough is caused by cancer.