Patients always have nasal discharge and phlegm for the following reasons: 1. This situation is related to acute and chronic inflammatory factors in the nasal cavity, sinuses and throat. 3.Patients may suffer from cold or flu, or respiratory tract inflammation and infection, which may cause pain, dryness, burning, foreign body feeling, phlegm blockage and other uncomfortable symptoms in the throat. The pharynx often produces mucus and pus phlegm, and some patients may also experience repeated backflow of nasal mucus from the nasal passages into the pharynx.