Possible causes: 1, upstream is often the inflammation of the nose, such as rhinitis, sinusitis, pus snot to the flow of stimulation of the pharynx caused by inflammatory irritation. 2, through the mouth, long-term stimulation of food, etc., and is poor nasal ventilation, open-mouth breathing air bacteria directly caused by. 3, downstream causes are often stomach diseases, such as gastritis, reflux esophagitis, acid reflux is the cause of pharyngeal inflammation is very hidden, but also many people ignore the disease 4, snoring at night open-mouth breathing is also the cause of dry throat discomfort in the morning.