Post-nasal drip Post-nasal drip Post-nasal drip (PND, also termed upper airway cough syndrome, UACS, or post nasal drip syndrome, PNDS) occurs when excessive mucus is produced by the nasal mucosa. The excess mucus accumulates in the back of the nose and eventually the throat once it drips down the back of the throat. It is caused by rhinitis, sinusitis, gastroesophageal reflux disease (GERD), or by a disorder of swallowing (such as an esophageal motility disorder). But also further sources such as an allergy, cold or flu and as a result of medications. However, researchers argue that the flow of mucus down the
Post-nasal drip back of the throat from the nasal cavity is a normal physiologic process that occurs in all healthy individuals. Post-nasal drip has been challenged as a syndrome and instead is widely viewed as a symptom by various researchers as a result of the wide variation amongst differing societies. Furthermore this rebuttal is reinforced due to the lack of an accepted definition, pathologic tissue changes, and available biochemical tests. PND may present itself through the constant presence of discomfort within an individual's upper airways as a result of the transportation of mucus from nasal membranes down the back of the throat