The throat feels clogged with phlegm, mainly due to nasal or sinus infection, chronic laryngitis, bronchitis and so on. 1. Nasal or sinus inflammation and infection: due to acute and chronic inflammation of the nasal cavity or sinus area, resulting in continuous production of inflammatory secretions, backflow into the throat, covering the surface of the throat, so that the throat feels phlegm clogged. 2. Chronic pharyngolaryngitis: due to acute inflammation of the throat repeated episodes, adverse physical and chemical factors such as stimulation and other etiological factors, can lead to pharyngeal mucosal hyperplasia and hypertrophy, increased glandular secretion, the surface of the throat sticky secretion adherence, can lead to the throat feel phlegm like a blockage. 3. Bronchitis: due to bacterial and viral infections, resulting in increased secretions in the bronchial tubes, while secretions in the pharynx stagnation, concentration is not easy to cough up, resulting in a feeling of phlegm in the throat. Such symptoms alone can not accurately determine the cause, but also need to be combined with the characteristics of the medical history and examination results in order to diagnose, it is recommended to consult a doctor in a timely manner, a clear diagnosis.