Excessive mucous secretion in the back of the nasal cavity or throat, causing sore throat and/or coughing. it is usually due to allergic rhinitis or a cold.

Post-nasal drip (PND), also known as upper airway cough syndrome (UACS), occurs when excessive mucus is produced by the nasal mucosa. The excess mucus accumulates in the back of the nose, and eventually in the throat once it drips down the back of the throat...