WHAT CAUSES A SORE THROAT?
A sore throat is most commonly caused by viruses that lead to a cold or flu. These viruses trigger inflammation at the infection site (along with the accompanying pain, redness, and swelling), signaling the body to send white blood cells and antibodies into the infected tissues to fight off the viruses. The soreness you feel in your throat is the direct result of this inflammation. Unfortunately, swallowing causes additional friction and pain because the irritated tissues slide over one another.
Having a dry throat can also cause your throat to feel sore when you have a cold or flu. For example, if you’re suffering from nasal congestion, you may need to breathe more out of your mouth, which can dry the throat and cause it to feel sore.