There is phlegm at the junction of the nasal cavity and the oral cavity, and the following factors should be considered in this case: i. The patient has rhinitis, which is mainly manifested as congestion and edema of the mucous membrane of the nasopharynx, as well as secretions. The junction of the nasal cavity and the mouth is the part of the nasopharynx. Second, to consider some nasal diseases caused by the backward flow of nasal mucus, mainly acute and chronic rhinitis, sinusitis, etc.. The current treatment, first of all, is nasal medication, you can use sea salt water in the nasal cavity for spraying, especially to use the sprayed sea salt water, not the flushed sea salt water, the sprayed sea salt water can reach the nasopharynx. The sprayed medications such as coleus and ryanodine. Then take some Chinese medicine, such as nasopharyngeal pellets, rhinitis gargle oral solution, etc.