Why Does the Nose Run When It’s Cold?

You step outside on a cold day, and within minutes your nose starts dripping even though you feel perfectly healthy. That happens because your nose is trying to warm and moisten the cold, dry air you breathe.

The inside of your nose is lined with moist tissue. As cold air passes over it, the nose adds warmth and water before that air travels farther into your respiratory system. Cold air can also stimulate the nasal lining to release more watery fluid. If the nose produces more moisture than it can move toward the back of the throat, the extra runs out of your nostrils instead.

Cold, Dry Air Makes Your Nose Work Harder

Air entering your lungs needs to be warmer and more humid than winter air usually is. Your nose helps make that adjustment using blood flow and moisture from its lining.

The colder and drier the incoming air is, the more noticeable this response can become. That’s why a nose may start running soon after you go outside but settle down once you return to warmer air.

You might also notice more dripping while walking quickly, running, or doing another outdoor activity. Faster breathing moves a greater amount of cold air through the nose, giving it more air to warm and humidify.

Why the Fluid Is So Watery

Cold-weather nasal drainage is often thin and clear because much of it is the extra watery fluid being produced in response to the air. It isn’t necessarily the same response that causes a runny nose when you’re sick.

A respiratory infection activates the immune system and can cause inflammation along with other changes in mucus production. Cold air can make the nose run without an infection at all. The timing is often the giveaway in everyday life: the dripping begins after entering the cold and eases when the cold-air exposure ends.

Cold wind may also make your eyes water. Because tears normally drain through small passages into the nose, that added moisture can make the dripping even more noticeable.

Some Noses React More Than Others

Not everyone’s nose responds to cold air with the same intensity. Some nasal passages are simply more sensitive to changes in temperature and humidity, so one person may need a tissue immediately while another barely notices anything.

Either way, the basic process is the same. A runny nose in cold weather is often the visible result of your nose doing its regular job: preparing each breath before it travels deeper into your body.

This article is for informational purposes only and is not a substitute for professional medical advice.