The presence of phlegm in the throat indicates that the inflammation is confined to the trachea or upper respiratory tract, and it is a good time to observe the color of the sputum. If it is yellow pus sputum, bacterial infection is generally considered; if it is white thin sputum, viral infection is generally considered. If an infant does not cough up sputum, there is no way to observe the color of the sputum, so you need to take your child for a routine blood test at this time. If it is a bacterial infection, there is usually an increase in white blood cells in the routine blood test; if it is a viral infection, there is usually no increase in white blood cells. If it is a bacterial infection that causes phlegm in the throat, you need to take some antibiotics for treatment, you can take three generations of cephalosporins, such as cefixime, which is more effective and has fewer side effects. If it is a viral infection, you can take Pudilan Anti-inflammatory Oral Liquid. In addition, taking the above two drugs at the same time, you also need to take some cough and phlegm class drugs, such as compound fresh bamboo liquid, the effect is still good.