Nasopharyngeal phlegm is always considered to be caused by rhinitis or sinusitis, chronic nasopharyngitis, lower respiratory tract infections and other reasons. 1. Rhinitis or sinusitis: when suffering from allergic rhinitis, acute and chronic rhinitis, the mucous membrane in the nasal cavity is congested and edematous, and the secretion increases, which can lead to the secretion backflow to the nasopharynx, resulting in the symptom of phlegm in the nasopharynx all the time. 2. Chronic nasopharyngitis: chronic pharyngolaryngitis patients due to long-term inflammatory stimulation of the mucosa of the nasopharynx, there can be an increase in secretions, so there will always be phlegm performance, often accompanied by coughing, coughing up phlegm, itching and other symptoms. 3. Lower respiratory tract infection: when suffering from bronchitis, pneumonia and other infectious diseases of the lower respiratory tract, the secretion of the trachea or lung tissue increases. Early nasopharyngeal secretions are sticky and can remain in the nasopharynx, leading to the sensation of phlegm in the nasopharynx all the time. If you have phlegm in the nasopharynx, you need to go to the hospital in time to find out the cause and standardize the treatment to avoid delaying your condition.