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 polyp cavity. Antrochoanal polyps usually arise in the maxillary sinus and extend into the nasopharynx and represent only 4–6% of all nasal polyps. However, antrochoanal polyps are more common in children comprising one-third of all polyps in this population. Ethmoidal polyps are usually smaller and multiple while antrochoanal polyps are usually single and larger. The true cause of nasal polyps is unknown, but they are thought to be due to recurrent infection or inflammation. Polyps arise from the lining of the sinuses. Nasal mucosa, particularly in the region of middle meatus becomes swollen due to collection of extracellular fluid. This extracellular