When suffering from cold and flu, upper respiratory tract infections, bronchitis, pneumonia, tuberculosis and other diseases, they are mostly accompanied by a cough. Coughing is a protective reflex activity and is caused when the respiratory tract is irritated in some way (e.g. inflammation, phlegm, etc.). Coughing causes a lot of pain to the patient, so some cough expectorants need to be taken. When taking cough expectorants, the following points should be noted: (1) Cough is only a symptom, not a disease, and when coughing occurs, cough expectorants should not be used alone. (2) Depending on the degree of coughing, there is a difference between a mild cough and a frequent and violent cough. A mild and infrequent cough helps to cough up phlegm, and when the phlegm is expelled, the cough will mostly be relieved naturally, so there is no need to take cough suppressants. Frequent and violent coughs can be painful and affect the patient’s rest and recovery, and in severe cases can cause emphysema, bronchiectasis, hemoptysis, etc. These coughs should be treated with cough suppressants. (3) There are two different types of coughs, dry cough and phlegm cough, and the use of cough suppressants should be different. It is possible to use cough suppressants alone for a dry cough, but if it is accompanied by phlegm production, care should be taken to use them together with expectorants to avoid affecting the discharge of phlegm and aggravating the cough and infection.