The cause of dry cough without sputum may be related to pharyngitis, bronchial asthma, tuberculosis, tumors and so on. 1. pharyngitis: pharyngitis patients often manifested as dry and itchy throat, cough, no phlegm, nausea when brushing teeth, pharynx feel a foreign body sensation, etc., accompanied by severe fever, cold, headache, earache. 2. Bronchial asthma: asthma patients often manifested as nose and throat itching, sneezing, runny nose, followed by chest tightness, dry cough. 3. Tuberculosis: early dry cough or a small amount of mucus sputum, coughing for more than 2 weeks when there is often blood in the sputum, inflammation spread to the pleura will have chest pain, dyspnea and so on. 4. Tumor: such as bronchial cancer, tracheal cancer, pharyngeal cancer, lung cancer, etc. Early stage will stimulate the mucous membrane of the respiratory tract, causing irritating dry cough without sputum, and late stage may cause yellow sputum due to infection, etc. Secondly, esophageal cancer, gastric cancer, etc., due to radiation and chemotherapy, which damages respiratory tract mucous membrane, will also cause irritating cough. There are more reasons for old dry cough without sputum, patients should go to the respiratory medicine department of regular hospitals in time to clarify the cause of the disease and get early treatment, so as to avoid delaying the condition.