Why does breathing through the mouth dry the windpipe and cause dry sore throat?

Nose humidifies more. Your respiratory system is designed with a natural humidifying organ, your nose. When you do not breathe through it, the air bypasses its humidifier and reaches the throat and lungs still dry. When you do breathe through your nose, the air is 100% humidified by the time it reaches those places. Your nasal membranes secrete about a quart of fluid a day, much of it water vapor reabsorbed in the lung.

Related Questions

How come breathing through the mouth dry the windpipe and cause sore throat, but not through the nose?

Hair Cells. When air is filters though the nose there are hair cells and mucous cells which help to clean ands sort of humidify the air. This is usually worse in winter when the heat comes on and the air lacks humidity drying out the mucous membranes. Read more...

Pain down right side of windpipe that gets worse as day goes on. No sore throat but feel pain if swallow when head is turned to left what could cause?

Pharyngitis. Still most likely an early sore throat with some swollen lymph nodes--that is why it is more sore when you turn to one side. Try taking Aspirin or aleve, (naproxen) fluids, gargle with warm salt water etc... If it gets worse and you develop fever, see a doctor. Read more...

Does mouth-breathing cause a sore throat which came with a fever?

Dryness. Mouth-breathing most commonly results in dryness in the mouth and relative dehydration. It should not, however, give anyone a fever. Read more...
Yes and no. Mouth breathing commonly causes a mild sore and dry throat that will improve with hydration. It by itself doesn't cause fever. A viral nasal infection will congest the nose making it easier to mouth breathe and cause fever but these symptoms are temporary once the viral illness runs its course. Read more...

Hi doctors, my breathing stops during my sleep, sore throat and enlarged tonsils plus sleep apnea. Help?

See your doctor. If you have diagnosed sleep apnea, presumably you have had a sleep study ordered by a physician. Please follow up with that doctor who can outline treatment plans given that diagnosis, or refer you to a sleep physician specialist. Read more...