Phlegm in the throat is related to voice habits, dietary habits, allergies, rhinitis, acid reflux and other reasons. 1. Voice habits: improper use of voice, such as teachers, singers, etc., due to the use of voice for a long time, loud voice, frequent use of voice, can lead to long-term stimulation of the pharynx and lead to edema, inflammation, the formation of phlegm. 2. Dietary habits: like smoking, drinking alcohol, easy to the mucous membrane of the throat caused by irritation; eat less vegetables, do not like drinking water, can cause dry throat, can cause chronic pharyngitis. 3. Allergy: contact with dust mites, dust, pollen and other allergens, stimulation of the mucous membrane of the throat can lead to chronic inflammation, causing inflammatory exudation, resulting in phlegm. 4. Rhinitis: Rhinitis can cause increased nasal secretion, change position, secretion reflux to stimulate the mucous membrane of the throat. 5. Gastric acid reflux: obesity, gastric diseases, etc., can lead to gastric acid reflux to the pharynx, damage and stimulate the mucous membrane of the pharynx, causing increased secretion of the glands. It is recommended that patients seek timely medical treatment and actively cooperate with doctors to treat the disease.