Phlegm is mainly a product of natural or irritated respiratory tract. Phlegm in the throat is mostly caused by respiratory tract infection or inflammation. Usually children will have phlegm in their throat when their cold condition worsens, especially viral colds, which can lead to inflammation in the body and greater stimulation of the respiratory tract to produce phlegm. Therefore, children usually cough up phlegm in the later stages of a cold. Another reason for more phlegm is that the child has a respiratory infection or pneumonia. The mucous membrane of the throat and bronchi etc. is greatly irritated by impurities and bacteria etc. invaded from outside, and phlegm is produced and moves toward the throat, where it collects and forms a large amount of oral phlegm. In this case, parents need to take their children to the doctor for treatment of infection or pneumonia. Most children have a poor ability to expel phlegm themselves and cannot cough up phlegm, so they can only remove phlegm from their throat by eliminating it or swallowing it. Therefore, they should drink more water or take some oral liquid that can clear phlegm. If phlegm accumulates more and has caused some blockage or obstruction to the respiratory tract, you can also use an aspirator to suck out the phlegm in their throat. Most children with phlegm have a cold or pneumonia that affects the health of the respiratory tract to produce more phlegm. In addition to active treatment of the disease, phlegm should be cleared properly.