The symptoms of bronchitis are often symptoms of upper sensation such as nasal congestion, runny nose and sore throat, followed by coughing, which is the main manifestation of bronchitis. As the cough worsens, some patients may experience pain behind the sternum, and a small number of patients may experience bronchospasm, which is characterized by shortness of breath and a tightening sensation in the chest. Most bronchitis is caused by viral or bacterial infections. The treatment of bronchitis is mainly cough expectorant, cough suppressants such as compound methocarbamol, dextromethorphan, pentoxifylline, etc., and phlegm-suppressing drugs such as acetylcysteine and tranylcypromine hydrochloride tablets, which are effective. If bacterial infection is combined, high ratio of white blood cells and neutrophils and high C-reactive protein in routine blood test are considered as possible combination of bacterial infection, which can be treated with antibacterial drugs.