Coughing up phlegm all the time can be seen in allergic pharyngolaryngitis, reflux pharyngolaryngitis, and pharyngolaryngitis caused by postnasal drip syndrome. 1. Allergic pharyngolaryngitis: contact with allergens in the mucous membrane of the throat can lead to irritation of the mucous membrane of the throat, resulting in congestion and swelling of the mucous membrane and continuous secretion of phlegm. Common allergens include airborne dust, dust mites, animal hair, etc. It is recommended to wear a mask when going out. 2. Reflux pharyngitis: This refers to the reflux of stomach contents into the esophagus and into the throat. Because the stomach contents are acidic, the mucous membrane of the pharynx does not have the same protective effect as the gastric mucous membrane, which can be corroded and cause inflammation. 3. Postnasal drip syndrome: increased nasal secretion, change of position can lead to nasal secretion backflow to the pharynx. Such as acute rhinitis, chronic rhinitis, sinusitis and other diseases can appear postnasal drip phenomenon, causing irritation to the throat. It is recommended that patients go to the hospital for examination and standardized treatment under the guidance of professional doctors.