Cold is an acute upper respiratory tract infection, and after treatment, post-infection cough will appear, which can be combined with or without sputum. If you have cough with no or little phlegm, you can use dextromethorphan and pentoxifylline to suppress cough; if you have cough with phlegm but it is not easy to cough out, you can use ambroxol hydrochloride and bromhexine to dissolve phlegm, and you can also do nebulization to help expectoration, and you can also use Chinese medicine to stop cough and expectoration, such as the syrup for acute bronchitis that is often sold in the market. When bronchospasm occurs, you can treat it with some wheezing medicines, such as theophylline, which can significantly relieve the more obvious symptoms of cough. If the cough persists without improvement, one should be alert to the possibility of complications of pneumonia.