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 irrigation cases of fatal naegleriasis have occurred due to nasal insufflation of the amoeba "Naegleria fowleri" from untreated tap water. Flushing the nasal cavity can soothe inflamed tissue and remove irritants like allergens; it may help clear mucus. The water should not be tap water, which may contain small amounts of bacteria that are safe to drink but may be dangerous in the nose. The water should be sterile or filtered for micro-organisms; if tap water is used it should be boiled. Saline solution is also sometimes used. A number of other compounds may be included in irrigation fluids such as