I am sure it is something everyone has experienced at some point. You’re walking outside on a cold day, the wind is blowing, and, of course, your nose is streaming. It’s an ugly thing at the best of times, but it’s made worse if, like me, you have a mustache that seems to almost take pride in absorbing the slick snot.

But why does this happen?

It’s a pretty simple explanation really and technically a good thing as a running nose in cold air means your nose is doing its job, albeit a grim one. When we breathe in cold air, our noses work to warm and humidify it before it flows into our lungs. This is achieved by the blood vessels in our nasal passages that dilate to increase blood flow and create more warmth.

In order to add moisture, however, the same process stimulates the production of mucus from our nasal glands. When it’s cold and windy, our noses can get a bit carried away with this process and produce too much mucus, which obviously starts to run out of our nostrils. Then, mixed with condensation from our exhaled breath or even moisture from the air, it can become more noticeable.

At the same time, windy weather can cause our eyes to water as they become irritated. This causes them to produce excess tears, which then trickle down our faces or start to drain through the little hole – the punctum – in the corner of our eyes, right next to our noses. The puncti drain into our sinuses and then into our nostrils, mixing tears with the excess mucus to make a more watery discharge.

These sticky compensation mechanisms are a normal part of our bodies trying to acclimate to changes in temperature. Around 50 to 90 percent of people experience running noses in cold, but some people are more prone to it than others – those with asthma, eczema, and hay fever tend to experience it more.

Dealing with this winter issue can be as simple as carrying tissues or a handkerchief with you, or if you have nothing else to hand, using a sleeve (yours or someone else’s). Wearing a scarf can also help, as this warms the air before it reaches our sensitive nostrils. Some trials have also shown that anticholinergic (drugs that block nerve signals) and anti-inflammatory nasal sprays can also help.

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.