Coughing and sputum after a cold may be caused by inflammation of the trachea due to the cold, however, it cannot be ruled out that a serious infection of the bronchial tubes or lungs has occurred, which leads to coughing and sputum. If there is no abnormality in CT, it is often due to tracheal inflammation, which is caused by congestion and edema of the tracheal mucosa due to inflammation, and also secretes a lot of inflammatory exudate, therefore, coughing and sputum will occur. Oral cough and phlegm medicines as well as anti-inflammatory drugs are more effective, and it is recommended to take Pudilan Anti-inflammatory Oral Liquid and Lung Power Cough Compound for treatment. If bronchitis or lung infection occurs, coughing and phlegm will also occur. The bronchial tubes or lungs will secrete a large amount of inflammatory exudates, and phagocytes in the body will gather at the inflammation site to engulf foreign bacteria or viruses, and subsequently these cells will undergo lysis and necrosis, which will also form phlegm and coughing symptoms will also occur, and intravenous anti-inflammatory drugs are needed for treatment.