Everyone knows the struggle of going outside on a chilly day, walking about 20 yards, when suddenly it is like Niagara Falls coming out of your nose.  It is gross, inconvenient, and quite frankly embarrassing for most, but there is one question that is asked, why does this happen to us?  The answer is what I decided to investigate.

There are about two major factors that cause runny noses according to Dr. Andrew Lane from John Hopkins, and those factors are respiratory biology and thermodynamics, a type of physics.  The biological factor has to deal with your bodies need to supply moisture to the nose.  Your body needs your nasal cavity to be warm and moist in order to function properly, so when it is cold out it sends more fluid to that area to keep it from getting dry, and that is where physics come into play.  Cold air does not hold as much moisture as warm air, that is also why you can see your breath in the cold as well.

It turns out that having a runny nose is not always a symptom of being sick, it is actually a symptom of your body working well!  Fluids being replenished is what your body is supposed to do, and the fact that a nose runs in the cold is perfectly normal.  However, a runny nose in the warmth could be a symptom of illness, most likely the common cold.

The reason people get more sick in the winter is actually because of the closeness we all are with each other in the winter, as opposed to summer when people could be both inside and outside for long periods of time.  This closeness makes it very easy for germs to jump from person to person.

Another interesting fact is that people also get more nosebleeds in the cold weather as well, and the answer is very similar to why we get runny noses.  We now know that when it is cold out there is less moisture in the air, and if the body isn’t supplying enough moisture to the nose it can cause it to dry out and eventually bleed.  To prevent these nosebleeds it is recommended to wear a scarf over your face, which keeps moisture in your nose area, or to use saline sprays to replenish the loss of fluid.

There are not many experiments that can be done to prove this fact, but physics provides a decent mechanism to explain why this annoyance occurs.  It is also obvious that it is not due to reverse causation, runny noses can’t change the weather, so until new information or studies occur, we will just have to assume that moisture is the reason for our sniffling problems.

So next time you are stuck outside in the cold and have a runny nose, don’t freak out and think you are sick, just put a scarf on your face and try and keep as warm as you can.