<unk>  <unk> , also known as upper airway cough syndrome (UACS), occurs when excessive mucus is produced by the<unk>  mucosa. The excess mucus accumulates in the back of the nose, and eventually in the throat once it<unk> s down the back of the throat. It can be caused by rhinitis, sinusitis, gastroesophageal reflux disease (GERD), or by a disorder of swallowing (such as an esophageal motility disorder). Other causes can be allergy, cold, flu, and side effects from medications. However, some researchers argue that the flow of mucus down the back of the throat from the<unk>  cavity is a normal physiologic process that occurs in all healthy individuals. Some researchers challenge<unk>  as a syndrome and instead view it as a symptom, also taking into account variation across different societies. Furthermore, this rebuttal is reinforced because of the lack of an accepted definition, pathologic tissue changes, and available biochemical tests.
Post-nasal drip
Nasal congestion
Burning mouth syndrome
Epiglottitis
Croup
Rhinosinusitis
Hajj Cough
Nasal polyp