Irritating dry cough is not necessarily a lung cancer, but it is important to rule out lung cancer. Irritating dry cough may be caused by foreign body in the airways, or mycoplasma infection or tuberculosis infection can cause irritating dry cough. Lung cancer can also cause irritating dry cough. To determine which kind of cough it is, we can do CT scan plus enhancement examination to see if there is any occupying lung lesion. If there is an occupying lung lesion, a puncture biopsy or fiberoptic bronchoscopy can be performed to obtain pathological tissue to understand the nature of the lesion, such as lung cancer, and cancer cells can be found through pathology. Bronchitis is mainly a chronic inflammatory change, while tuberculosis can manifest as infection, caseous necrosis, and antacid bacilli can be found inside, and anti-tuberculosis treatment is effective. In conclusion, irritating dry cough is not necessarily lung cancer, but it is important to exclude lung cancer, especially in middle-aged and elderly men who are long-term smokers.