Peradventure have you heretofore had a runny nose? Maybe did you get rid of it? Of course you got over it! You won't treat a runny nose directly, nevertheless your body generally establishes immunity to a specific cold infection within a couple of days. That is called treated by your own immune response!

Adults have previously had a great deal of the cold viruses. Adults have actually created immunity to the colds they have had. So there are not quite as many cold viruses existing for adults to become infected with. That is why grownups just succumb to a few colds each year and kids acquire a dozen runny noses per year.
https://independent.academia.edu/SiegalDung