(I) Sinusitis is usually prompted by a cold, but may
occasionally be caused by a bacterial or fungal
infection. (II) In some people, allergies can cause
sinusitis as well. (III) Unless the symptoms are severe or
long-lasting, they will probably get better without
treatment. (IV) If one has small sinus drains or a
deviated nasal septum in which the cartilage between
the nostrils is out of place, he or she may also have
sinus problems. (V) Pregnant women are especially
susceptible, as their hormones can make the nose swell
and increase mucus production.