There are many reasons why there is white phlegm in the throat, as follows: 1. Chronic inflammatory diseases occur in the throat, often because of the usual work, life, excessive voice, or usually more smoking, drinking, eating spicy, stimulating food, exposure to air pollution, etc., resulting in chronic inflammatory conditions in the throat, the mucous membrane glands of the throat are prone to repeatedly secrete mucus, or even mucopurulent secretions. 2, some patients may have a certain degree of nasal, sinus inflammatory infectious and allergic disease conditions, various types of nasal secretions, may further backflow into the pharynx, may also lead to the pharynx is always the symptom of white sputum, if necessary, need further detailed examination.