The Mayo clinic says that a runny nose is known as rhinorrhea. This fancy name simply means you have swollen nasal tissues and blood vessels. They fill with excess fluids and mucus, which escape through your nose and trickle down the back of your throat. Although most runny noses clear up on their own without treatment, you can speed up the process with over-the-counter medicines. They will give you relief from this very annoying problem.
A runny nose can be caused by allergies. According to the Mayo Clinic, this is especially likely when you also have watery, itchy eyes and are sneezing. Dr. Robert Enberg of the Henry Ford Hospital in Detroit says that up to 80 percent of runny noses are triggered by allergies rather than by colds or the flu. Over-the-counter antihistamines can help relieve your runny nose and other allergy symptoms.
The Real Age website says over-the-counter decongestants can stop a runny nose. They are available as pills or nasal sprays. However, they should not be used for longer than three days, or they could make the problem worse because they can have a rebound effect. They can also dry out your sinuses, causing irritation of the linings.
Some over-the-counter medicines combine an antihistamine and a decongestant. One pill attacks a runny nose with the two most commonly used remedies. Real Age says they tend to be more effective than taking an antihistamine on its own, so you can use them when your runny nose is particularly stubborn and is caused by a cold or the flu.