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
Mucus nasal or airway mucus and prevented from entering the system. This event along with the continual movement of the respiratory mucus layer toward the oropharynx, helps prevent foreign objects from entering the lungs during breathing. This explains why coughing often occurs in those who smoke cigarettes. The body's natural reaction is to increase mucus production. In addition, mucus aids in moisturizing the inhaled air and prevents tissues such as the nasal and airway epithelia from drying out. Nasal and airway mucus is produced continuously, with most of it swallowed subconsciously, even when it is dried. Increased mucus production in the