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
Nasal meatus the nasolacrimal canal. Nasal meatus A nasal meatus is a nasal passage of the nasal cavity, of which there are three; the superior meatus, middle meatus and inferior meatus. These nasal meatuses are also known as meatus nasi superior, meatus nasi medius, and meatus nasi inferior. (A "meatus" is a passage or opening in the body, especially one which is open to the exterior). The nasal meatuses are located beneath each of the corresponding nasal conchae. In the case where a fourth, supreme nasal concha is present, there is a fourth supreme nasal meatus. The superior meatus is the smallest