The nasal congestion that results blocks the sinuses, preventing drainage of mucus into
and mouth. The sinus mucus then builds up and thickens, and infection
in the sinuses become
s more like
ly. Infectious sinusitis can also be caused by a bacterial infection or some
s by a fungal infection.
Allergic sinusitis is caused by an allergic reaction to
dust, mold, pollen, or another substance in the environme