Cough is one of the most common symptoms of the respiratory system and is a protective measure of the body. For occasional, mild coughs, it is not necessary to take cough suppressants. Medications should be used to treat cough only if it is severe and frequent, seriously interferes with life and rest, or may lead to complications. Coughs can be divided into coughs without phlegm, coughs with phlegm, coughs with thick phlegm and coughs with pus phlegm according to whether they are accompanied by coughing phlegm and the nature of the phlegm, and these four conditions should be treated separately. 1.Cough without phlegm: dry cough without phlegm and irritating choking cough, use cough suppressant. Cough Bichin (pentoxifylline citrate tablets): It can selectively inhibit the cough center and has a local anesthetic effect on the respiratory tract mucosa, so it has both central and terminal cough suppressant effects and is non-addictive. Therefore, it is often used for dry cough without sputum and whooping cough caused by upper respiratory tract infection. Cough syrup containing codeine: Various cough syrups containing a small amount of codeine can also be used for dry cough, which can exert the strong cough suppressant effect of codeine without addictive properties, and is also one of the ideal cough suppressants. In case of severe dry cough with chest pain, codeine can be taken under the guidance of a physician, and the most important feature of this drug is its rapid and powerful effect on cough. Note: Because this drug is a narcotic drug, the management is very strict, not long-term use. 2. Cough with phlegm: phlegmatic cough, use expectorant drugs. Patients with cough with phlegm are prohibited from taking central cough suppressants, otherwise they will inhibit the cough reflex and lead to phlegm obstruction of the airway, causing asphyxia or aggravating respiratory tract infection. Expectorants and cough suppressants: phlegmatic cough is caused by chronic bronchitis, etc. Expectorants and cough suppressants can be used, such as ammonium chloride or potassium iodide. These two drugs are nauseating expectorants, which can stimulate the gastric mucosa after oral administration, reflexively causing a large increase in respiratory secretions and easy coughing up of phlegm after being diluted, thus achieving expectorant effects. Compound licorice tablets and brown combination can be used. There are also herbal formulas for relieving cough and resolving phlegm, such as Chuanbei loquat, snake bile and Sichuan peel liquid, Luohango cough suppressant punch, snake bile and Chenpi liquid, and Tongxuan lung pill. For patients with coughing phlegm, in addition to medication, they should drink more water to dilute the phlegm to facilitate coughing out. 3. Cough of thick phlegm: if the phlegm is thick, use phlegm dissolver; if the phlegm is thick and not easy to be expelled, choose phlegm dissolver. Sputum easy net (acetylcysteine): this drug can decompose the mucin in sputum, reduce the viscosity of sputum, so that sputum can be coughed out smoothly; must be cushioned (bromhexine): it can decompose the mucopolysaccharide fiber in sputum, reduce the viscosity of sputum, and make it easy to cough out; Mucosolvan (aminobromine): in addition to thinning sputum, it can also promote cilia movement and protect bronchial mucosa, which is a more ideal expectorant drug. 4, cough of pus sputum: yellow and green pus sputum, using cough suppressant and phlegm-transforming medicine with antibacterial agent. When the sputum is yellow or green pus sputum, it means that it is accompanied by infection, so in addition to the selection of cough suppressant and phlegmolytic drugs, antibacterial drugs need to be added. Those who are in a position to do so need to visit a hospital and send sputum culture for examination, and choose antibacterial drugs for treatment according to the results. In addition, when cough and sputum are accompanied by croup, in addition to cough-expectorants, it is necessary to add wheezing drugs, such as oral aminophylline and ketotifen, etc. In some cases, the cough is caused by gastroesophageal reflux, and gastric motility promoters (such as morpholine) and acid suppressants (such as metformin, etc.) should be used.