There are many reasons why an irritating dry cough can occur, such as infection by mycoplasma, viral infection, caused by drugs, cough variant asthma, cardiac insufficiency, etc. Therefore, when patients have persistent cough, they need to actively improve the relevant examination to clarify the diagnosis and take targeted treatment according to the diagnosis: irritating dry cough, the clinical causes are as follows: 1. stimulation by various physical and chemical factors: for example, patients who smoke for a long time. The stimulation of smoke will lead to a long-term dry cough without sputum; 2. Allergy: whether it is drug or food allergy, pollen or paint allergy, it may lead to a dry cough. No sputum is due to the stimulation of physical and chemical factors, and allergy does not lead to an increase in respiratory secretions, and if it leads to an increase in secretions, it is impossible to have no sputum. 3, various infections: such as Mycobacterium tuberculosis infection, chlamydia, mycoplasma infection, viral infection, fungal infection, may lead to respiratory tract, and the increase in mucus secretion is less likely, so the patient will also have a dry cough without sputum; 4, bronchial lung cancer: it can also lead to patients to cough for a long time without sputum, or dry cough without sputum. 5. Cough variant asthma: its clinical manifestation is only cough without wheezing. The pathology is the same as that of bronchial asthma, which is a persistent non-bacterial inflammation in the airways, leaving the airways in a state of hypersensitivity, so fumes, car exhaust or even minor stimuli, such as changes in the temperature, humidity and flow rate of inhaled air, can stimulate coughing. 6. Cardiac insufficiency: most patients with cardiac insufficiency have pulmonary stasis thus predisposing them to lung infection and thus coughing symptoms. In conclusion, there are many causes of dry cough without sputum, infections, and non-infections. Among the non-infections, special attention should be paid to autoimmune system diseases due to tumors, which can also lead to dry cough without sputum. For a specific patient, the cause of an irritating dry cough without sputum usually has to be analyzed and judged specifically.