why does your nose create mucus when you get a cold?
It's quite common, yet highly annoying -- a runny nose. Your nose drips when your nasal tissues and blood vessels produce excess fluid or mucus, according to the Mayo Clinic. This excess fluid also runs down the back of your throat in the dreaded post-nasal drip. Sometimes you'll have nasal congestion along with your runny nose, but not always. Dozens of things can cause your nose to run, from a variety of allergies and illnesses to more serious conditions like a deviated septum. Certain medications, stress and even pregnancy can also cause a runny nose.