It is called DNS
(deviated nasal septum)
Do saline gargles daily.
Whenever possible do steam inhalation also.
Cover your nose and mouth with hanky for at least 30 sec when you go in dusty areas also when you go in and out of AC. As our nose is the most sensitive part of our body, When there is temperature difference between two rooms or inside n outside, then if we not protect our nose, it gets affected.