If you have ever had a cold, allergies, been out in the cold, or, if you’ve just had a good cry (so, basically, if you are a human being), you probably know exactly what it feels like to have a runny nose. And, you probably know how annoying it feels to have a runny nose. Between always carrying tissues on you, to having your nose run at the worst moment possible, it’s always a drag to have a runny nose. Although having a runny nose when you have a cold or allergies might make sense, Why does your nose run when it’s cold?
Rhinorrhea is the medical term used for a runny nose. If your rhinorrhea seems to happen when it’s cold outside, it’s due to two main reasons. One of the main reasons for having a runny nose during the colder seasons is biological. When you breathe in cold air through your nostrils, your body wants the air to warm up before it hits your lungs. Small blood vessels in your nostrils open wider to help warm up and also humidify the cold, dry air. But that extra blood flow and humidity leads to more mucus production.
Why does your nose run when it’s cold – Physics
The second reason that can help explain why your nose starts to run whenever it’s cold outside has to do with thermodynamics. Water vapor is a part of every breath we exhale. You can see this when the weather is particularly cold. When you breathe in warm, humid air, you will actually be able to see your breath. This is also partly why your nose is runny during the winter: when the warm air inside your nostrils meets the cold air outside, moisture builds inside your nostril and contributes to that nasty mucus.
People who exercise outside when it’s cold will be especially prone to having a runny nose. Known as “skier’s nose”, this occurs because your breathing will become more intense as you exercise, meaning more moisture and more mucus in your nose.
So how do you stop your nose from running? If it’s due to allergies or a flu, you can take antihistamines or flu medicine to try and lessen your runny nose. But if it’s just cold outside, your body will basically always find a way to make your nose run. Our advice? Keep a tissue handy when you’re out in cold weather, and when you start to feel the drip, well, blow your nose!
+ Bonus Knowledge Nuggets
Do you know why your nose runs when you cry? Although you would only expect to have liquid come out of your eyes, when you cry, tears come out of the tear glands under your eyelids and then drain through the tear ducts. The tear ducts empty into your nose. Your tears mix with mucus in your nose, which is what makes your nose run when you cry!
Show Me the Proof