The symptoms of coughing in respiratory tract infection indicate that the infection has entered the airway, and there is a possibility that it will go further down the small airway. Because coughing has a two-way force, the respiratory tract is a tube, coughing is equivalent to exerting a spasmodic pressure in the middle, then let the airway contract a little, this time part of the dirty things will be discharged from the oropharyngeal cavity with the cough. However, if there is inflammation or secretion under the contracted position, it will be squeezed into the lungs by the pressure of coughing, which will cause the infection to enter deeper. This is why it is important to clear the lungs and use phlegm-eliminating medication when this cough occurs. If you use western medicine, you need to identify whether it is a viral or bacterial infection and take the appropriate antiviral or antibacterial treatment. If you use Chinese medicine, you must clear the lungs and dissolve the phlegm instead of using cough suppressants.