Viral infections, such as the
flu, cold, croup, mononucleosis, measles,
and chickenpox.
Bacterial infections, such as strep throat or tonsillitis, which can cause severe pain and difficulty swallowing.
Sinus or nasal passageway infections, which can cause postnasal drip and irritation of the throat.
Allergies, which can trigger inflammation and mucus production in the throat.
Acid reflux, which can bring stomach acid up into the throat and cause burning and inflammation.