So, Why Does Your Nose Always Run When It’s Cold?

A nose that drips like a faucet in winter is business as usual for many people, especially those with chronic allergic or nonallergic rhinitis. It’s even got an official diagnosis: cold-induced rhinorrhea, or skier’s nose. In a study in the journal Annals of Allergy, researchers found that 96 percent of people polled reported experiencing some degree of the condition, and 48 percent reported having a more moderate or severe case.

Apparently, getting a runny nose when we step out into a chilly winter breeze is a bodily defense mechanism, according to Murray Grossan, MD, of the Grossan Sinus and Health Institute. That’s because the nose has two main purposes: 1) to filter bacteria so they don’t reach our lungs, and 2) to warm the air before it reaches our lungs. “In cold weather the cilia, the tiny oars that move mucus along, are slowed,” explains Dr. Grossan, who is also author of The Whole Body Approach to Allergy and Sinus Relief. “ When cilia slow, bacteria remain in place and multiply, and this is why people get sick in the winter.” Not that the nose isn’t trying to keep you healthy. All that dripping you experience is the nose working overtime to produce more fluids to help move bacteria along. Dr. Grossan says to help it out, trying physically warming your nose when you come inside: “Rub your hands together, and then breathe into cupped hands or inhale steam from hot green tea and drink it, as green tea stimulates cilia.”

Our nose runs in winter for one more purpose, which is to combat the drier outside (and inside) air. “It needs to humidify the air we breathe in, which is done by the mucus and various secretions in our nasal cavity,” says Ehsan Ali, MD, of Beverly Hills Concierge Doctor in California. “In winter, or when it’s cold outside, the air is much drier than in the summer, which is more humid. Our noses respond by producing more secretions and mucus to help humidify the air to a level our bodies need.” When there’s a lot of fluid being produced, that’s when it starts to run out of the end of your nose. (Related: Check out the surprising reasons you have sniffles year-round.)

from Reader's Digest http://www.rd.com/health/conditions/nose-runs-when-its-cold/