Coughing for a month is not good, mainly due to the following reasons: First, the selected drug is not sensitive to it, it is recommended to review the sputum culture, according to the results of the sputum culture to select sensitive antibacterial drugs, to be anti-infective. Secondly, cough is a rare disease, such as reflux esophagitis, where conventional antibacterial drugs and cough and phlegm medicines are ineffective, mainly due to acid reflux into the throat, which stimulates the throat and causes coughing and phlegm. Thirdly, allergic cough, which is caused by contact with allergens, requires oral anti-allergy medication to improve the cough.