Bronchitis causes coughing, mostly accompanied by coughing and phlegm. Bronchitis is an inflammation of the bronchial mucosa and its surrounding tissues caused by repeated infections with viruses and bacteria, and is divided into acute bronchitis and chronic bronchitis, both of which cause coughing. When pathogenic bacteria damage the bronchial mucosa, they irritate the mucosa, leading to increased cellular secretion. In addition, cough receptors in the bronchial tubes are stimulated when infected by pathogenic bacteria, resulting in coughing and coughing up sputum. In some patients, symptoms such as dyspnea, sore throat, chest pain, etc. may occur in severe cases. A physical examination, along with blood tests, chest CT or X-ray, C-reactive protein, etc., are required to confirm the diagnosis of bronchitis and select targeted medication.