People living in arid climates or dry conditions often experience dehydration due to low water intake. This may also cause uvula
swelling, as when the body has a dearth of water, the uvula
is forced to soak in saliva.
The condition is common among smokers, and those who work in highly polluted areas. Smoking and other pollutants or irritants dry up the uvula and cause itching, which causes the swelling.