There is mucus phlegm in the throat can not cough out, consider more than due to chronic laryngitis, chronic bronchitis, upper respiratory tract infections and other effects caused by. 1. chronic pharyngitis: mainly due to acute pharyngitis caused by repeated episodes of chronic inflammation of the mucous membrane of the pharynx, will be manifested in the throat parts of the foreign body sensation, dry itchy pain, dry cough, hoarseness, etc., but also in the throat there is mucous phlegm coughing out symptoms. 2. Chronic bronchitis: mostly due to infection or non-infectious factors leading to the trachea, bronchial mucosa and inflammation of the surrounding tissues, will be manifested as coughing, coughing up sputum, wheezing, shortness of breath, coughing up sputum with blood, etc., due to the sputum viscous, can be adhered to the mucous membrane of the posterior wall of the pharynx is not easy to cough out. 3. Upper respiratory tract infection: mainly refers to the nasal cavity, pharynx, throat parts of the acute inflammation of the infection, will be manifested as coughing, sneezing, nasal congestion, tonsils enlarged, congestion, throat with mucus phlegm can not be coughed up and so on. If such symptoms occur, they should be clearly diagnosed after systematic examination by a specialist.