Patients with bronchitis usually have the doubt that they obviously have phlegm, but they cannot easily cough it up. First of all, we need to see if the patient has obvious infection. If there are obvious symptoms such as cough, sputum, chest pain and fever, bacterial infection is considered and the infected person should be given oral antibiotics. If the patient has phlegm that cannot be easily coughed up, he should be given cough and phlegm supportive drugs, such as ammonium chloride licorice combination, tranylcypromine, acetylcysteine, etc. Nebulization therapy can also be used to dilute the phlegm in the airways and promote the expulsion of phlegm. If it is mucous sputum with dyspnea, inhalation of aerosol will help.