Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: Fred1231 on 12/10/2011 21:40:25

Title: Why sneeze through your mouth not through your nose?
Post by: Fred1231 on 12/10/2011 21:40:25

Hi, this question's about the purpose of sneezing. When normal things like dust or pepper irritate my nose, I let out one or two fairly forceful sneezes, expelling a lot of droplets, and afterwards the tickle's completely gone. But the problem is that pretty much the entire blast of air, and all the droplets, come from my mouth. The only time mucus is ever expelled from my nose is when it's very, very runny, and even then, it's not all that much. I have even put things under my nose as I sneezed, to see if any droplets would show up, and none ever did. This contrasts with my mouth, which sprays out a ton of droplets. I would think I was just weird, except that everyone else that I see sneeze seems to do it exactly the same as I do, sneezing out of their mouth, with nothing normally coming from the nose. So, if the point of sneezing is to expel irritants from our nose, why does this happen? I've heard various explanations, such as the mouth serves as a release valve, or that if you just sneeze with your mouth closed and it will come out of you nose. The mouth being a release valve would make sense, except that don't really see anything coming from my nose. When I try to sneeze with my mouth closed, it just turns into a painful stifle. Given all this, I'm not too sure that the purpose of sneezing is to blast particles from the nose. What to you guys think?

Title: Why sneeze through your mouth not through your nose?
Post by: CliffordK on 13/10/2011 14:08:23

Humans have the Uvula which opens or shuts the nasal passage, although I believe the uvula can become inflamed when you have a cold, and may not function as well as normal.

I would imagine the forces involved in a cough/sneeze would be damaging to your nose if the mouth was shut and the entire force would be directed through the nose.  And, thus one tends to shut the uvula, shut one's eyes, and let out a sneeze. 

You are right, it is odd that irritation in the nose would cause a sneeze out the mouth, however, the sneeze reflex would be to protect the lungs and major airways.

Title: Why sneeze through your mouth not through your nose?
Post by: Fred1231 on 13/10/2011 16:09:39

Thanks for your answer. I'm sure you're right about it helping to protect your other airways.  But it seems that a sneeze does more than just that, since the itchy feeling in my nose is always completely gone afterwards.  I notice that that my nose usually tends to feel a bit runnier afterwards, and when I have nasal congestion, the sneeze helps relieve it for a few seconds. Not really sure exactly what's happening, but it definitely gets rid of the tickle. 

Title: Re: Why sneeze through your mouth not through your nose?
Post by: jlschandler on 30/09/2017 17:42:23

Quote from: Fred1231 on 12/10/2011 21:40:25

Hi, this question's about the purpose of sneezing. When normal things like dust or pepper irritate my nose, I let out one or two fairly forceful sneezes, expelling a lot of droplets, and afterwards the tickle's completely gone. But the problem is that pretty much the entire blast of air, and all the droplets, come from my mouth. The only time mucus is ever expelled from my nose is when it's very, very runny, and even then, it's not all that much. I have even put things under my nose as I sneezed, to see if any droplets would show up, and none ever did. This contrasts with my mouth, which sprays out a ton of droplets. I would think I was just weird, except that everyone else that I see sneeze seems to do it exactly the same as I do, sneezing out of their mouth, with nothing normally coming from the nose. So, if the point of sneezing is to expel irritants from our nose, why does this happen? I've heard various explanations, such as the mouth serves as a release valve, or that if you just sneeze with your mouth closed and it will come out of you nose. The mouth being a release valve would make sense, except that don't really see anything coming from my nose. When I try to sneeze with my mouth closed, it just turns into a painful stifle. Given all this, I'm not too sure that the purpose of sneezing is to blast particles from the nose. What do you people think?

I have this same question and NONE of the online response seems to address it satisfactorily!
I sneeze many times a week and most of them catch me - and everyone around me - completely by surprise because they are loud explosive sneezes.  I don't have allergies and I don't have a cold.  I just sneeze a lot.  And the air ALL comes out my mouth - I can feel all the action in my throat.  Seriously - no physiological explanations online accurately describe and explain the process.   

Title: Re: Why sneeze through your mouth not through your nose?
Post by: evan_au on 01/10/2017 19:56:16

Quote from: jlschandler

I sneeze many times a week and most of them catch me - and everyone around me - completely by surprise

Could this be a photic sneeze reflex, where you sneeze when coming out of a dark room into bright light outdoors?
See: https://en.wikipedia.org/wiki/Photic_sneeze_reflex

Title: Re: Why sneeze through your mouth not through your nose?
Post by: Bored chemist on 01/10/2017 22:35:54

I think you sneeze through your mouth because you have forgotten how to do it properly.
Babies know how to do it.

Sometimes spectacularly.
https://www.theverge.com/2016/6/29/12058224/baby-nose-pasta-gifs