4. Smoking or Air Pollution
Cigarette smoke and environmental pollutants irritate the lining of your respiratory tract, causing it to produce extra mucus as a protective measure.
5. Gastroesophageal Reflux (GERD)
Acid reflux can cause stomach acid to reach your throat, leading to irritation and excessive mucus production. People with GERD often feel a lump in their throat or frequent throat clearing.