Sniff. Sniff. Is your nose running? Better go catch it!

OK, so that’s an old joke and probably not a very good one either. But runny noses are something all of us have to deal with from time to time.

So what is it that runs out of your nose when it’s runny? That’s called mucus. Your nose and the sinuses in your head make about a quart of mucus every single day!

Mucus is probably not something you want to give a lot of thought to. After all, it is sort of icky. But it does do important things for your body. Mucus keeps bad germs, bacteria, pollen and other harmful things in the air out of your lungs by trapping them in your nose.

As mucus stops these things and builds up inside your nose, it often dries out and you need to blow your nose to get the harmful things out before they start to irritate your nose. If your nose does start to get irritated, you might have to sneeze to expel the harmful invaders.

At other times, though, mucus might run out of your nose for several different reasons. When this happens, we say you have a runny nose, and it’s time to reach for the tissue box. Of course, scientists and doctors have a fancy name for a runny nose. They call it rhinorrhea.

For example, when you get sick with a cold or the flu, your body senses that it’s under attack. In response, it begins to make even more mucus to fight off the invading germs, so you don’t get even sicker. When this happens, the mucus has to have some place to go, so it comes out of your nose, drains down your throat and sometimes even clogs your sinuses, making your head feel stuffy.

A similar thing occurs in people who have allergies. If you’re allergic to something, whether it’s pollen in the air or hair from an animal, your body sees those things as invaders, like germs, when you come into contact with them. When that happens, your body starts making more mucus, just like when you have a cold or the flu.

A runny nose can also happen when you cry. This is because your tears drain through tear ducts that empty into your nose. Inside your nose, they mix with mucus and your nose starts running.

You might also notice that your nose runs when it’s really cold outside. This happens because your nose tries to warm up the cold air before sending it down to your lungs. Blood vessels inside your nose open up to allow more warm blood to come to your nose to help warm the air. This also causes more mucus to be produced, which makes your nose run.

A runny nose can be a pain, but most doctors usually don’t worry about it too much, since it’s not considered a serious problem. However, if you have allergies at certain times of the year, a doctor may prescribe an antihistamine for you that will help reduce runny noses and help you feel better.


90 Join the Discussion

1 Star2 Stars3 Stars4 Stars5 Stars  (17 votes, avg. 3.76 out of 5)
  1. Hey Wonderopolis! Did you know you can also get a runny nose from just sneezing? Like, if you sniff pepper (which, by the way, is an old wives’ tale) you sneeze and then your nose starts running. You can find all sorts of stuff like that in a book called “Grossology”. :)

    By the way, I think that tomorrow’s wonder is about mythology! I <3 Mythology!

    • Thanks for telling us about that book, Abby! We’ll have to check it out! We appreciate you sharing what you know about runny noses…THANK YOU! We like your guess about tomorrow’s Wonder, too! We’re glad you like mythology…we’re pretty sure there’s a Wonder of the Day® coming up sometime in the near future that you will REALLY enjoy! :-)

    • Thank you for sharing your opinion about today’s Wonder, Sydney! We appreciate and respect it!

      Some Wonder Friends LOVE learning about things that other Wonder Friends might think are gross. They like learning about the human body, stinky smells and creepy crawling critters! We think it’s WONDERful that different people like different things! :-)

    • Hello, Hannah! Are you talking about the tissue “person” in the video? We think the tissue person is made from paper and is wearing it, too! Thanks for being a GREAT Wonder Friend and leaving us a comment today! :-)

    • Thanks for sharing your personal connection to today’s Wonder, Gloria! Your sister’s nose could be running for a number of reasons! We encourage you to re-explore today’s Wonder to find out what those reasons might be! :-)

    • Thanks for letting us know what you thought about today’s Wonder, Michael! We appreciate your opinion and hope you’ll visit Wonderopolis again tomorrow! :-)

  2. I like learning about gross stuff and this one was fuuuuuuuuuuuunnn. Thanks for this one, wonderopolis. I love ya!!!!

    • We think it’s SUPER that you liked today’s Wonder, McKenzie! Thanks so much for letting us know that you thought learning about runny noses was FUN! :-)

    • That’s a GREAT question, Slaneyy! We’ll both have to do a bit more WONDERing about it! Thanks for stopping by Wonderopolis today for some WONDER-filled learning! :-)

    • Your comment ROCKS, Brandon! We are SUPER HAPPY that you always learn WONDERful things in Wonderopolis…we do, too! Have a GREAT Wednesday! :-)

  3. That was a lot of information about runny noses! We really liked today’s video, it was funny. Is tomorrow’s wonder about Wonderopolis or monsters? We think it’s very interesting to find out why we have runny noses: because we are sick, we are trying to warm air or when crying. Hope you have a Wonderful Day, and your noses stays still.

    • Ha, ha! We haven’t had to catch our running noses yet today, Mr. Draper’s Class, so thanks for helping us hope that they stay still! Your comment made our morning! Thank you for sharing all the COOL things you learned about runny noses today…you guys are AWESOME Wonder Friends! :-)

    • That is a GREAT question, Sally! It would make a WONDERful future Wonder of the Day®! Thanks for WONDERing about runny noses and mucus with us today! It’s fun to learn in Wonderopolis! :-)

  4. Hi wonderopolis! Some people also call mucus “snot.” What do you call mucus? Have a happy, fantastic, wondering day.

    • Thanks so much for wishing us a happy, fantastic, WONDERing day, Kayla and Kelly! We really appreciate it! We like to call it “mucus” mostly, but we think LOTS of Wonder Friends like to call it “snot” because that’s a really fun word to say! :-)

  5. Today’s wonder was fun! I enjoy learning new things! I think tomorrow’s wonder will be about a weird critter! Wonderopolis is great!!

    • We think YOU are GREAT, too, Vickie! Thank you for sharing that you thought today’s Wonder was FUN…we did, too! We will have to visit Wonderopolis tomorrow to see what new, exciting, WONDERful things we will all be WONDERing about! :-)

  6. What a coincidence! I have a cold, and my nose is running like crazy!
    I hope my cold goes away. :(

    I think tomorrow’s Wonder is about myths or legends.

  7. Dear Wonderopolis,
    We haven’t visited in awhile because our class has been busy, but it’s great to see you again!
    Ella liked the funny video. Michael was tricked because he did not know what the title of today’s wonder meant. Katie said the tissue man was weird!
    See you soon,
    Kids in Room 305

    • It’s so great to hear from you, Ella, Michael, Katie, and ALL of your WONDERful students, Mrs. Kennedy! Thank you for visiting today’s Wonder with us and for leaving us this GREAT message to let us know you stopped by! We hope you all have a GREAT day! :-)

    • Hello there, Jelin! We’re glad you enjoyed exploring today’s Wonder and learning some cool new facts about runny noses! :-)

    • We appreciate you sharing what you think about today’s Wonder, Isha! Thank you! We also really like your guess for the next WONDERful Wonder…we can’t wait to visit Wonderopolis tomorrow! :-)

  8. Why does snot come out of our noses? Why could we just sneeze without the snot? I just don’t get it. Why do we make noise when we sneeze?

    • Hi, Mehar! Those are all GREAT questions! Sneezing helps our bodies “expel” or “get rid of” irritants and things that might cause us harm. Mucus traps germs and other bad things, so if you think about it, we might really want “snot” to come out instead of staying in! You can learn more about why we sneeze by visiting past Wonder #331 – Why Do You Sneeze? :-)

  9. Dear Wonderopolis,

    We’re wondering if tomorrow’s Wonder will be about lying or tall tales.

    We loved the video clip today! We also want to try making some of those tissue box crafts, especially the race cars. :)

    Have a great day!

    • Those tissue box race cars do look like a lot of fun, Miss Kirsten’s Kindergarten GT Class! We were thinking that making crafts like that is also an awesome way to spend time with friends and family! We really like your guesses for tomorrow’s Wonder. Hmmm…we WONDER if you guys are right? We can’t wait to find out! :-)

  10. Hey wonderopolis!! I wanted to say hey and this is a nasty, weird, and interesting wonder. I love wonderopolis, but some of the wonders are nasty and crazy. BYEEEEEEEE WONDEROPOLIS!!!!!!! GROSS WONDER, BUT COOL AND FUNNY!

    • We like the SUPER adjectives you used in your comment to describe today’s Wonder, Emily! Way to go! Thank you for letting us know what you thought, too! It means a lot to us when our AWESOME Wonder Friends (like YOU!) tell us what they think about the Wonder of the Day®! :-)

    • That’s an interesting question, Mr. Flab! We like the creativity of the comments you leave for us when you visit Wonderopolis! We think your Wonder brain ROCKS! :-)

    • Hi, Jenna! We try our hardest to reply to every comment our WONDERful Wonder Friends leave for us, and we also try to answer questions in those comments the best way we can! We appreciate the comments YOU left for us on the Wonders about boomerangs, blue cheese, water towers and snails and slugs! We hope you re-visited those Wonders later to see how we replied to your comments! Thanks for being a GREAT Wonder Friend! :-)

  11. Hey Wonderopolis, I haven’t been on your site too much anymore. I try to, but either I’m doing my ice hockey practice or field hockey practice or doing my homework on the computer. You know what? Go to this wonder at around 7:20 or 7:30 and I will be there every night.

    • Thanks so much for leaving us this GREAT comment, Mushkale! We know LOTS of our Wonder Friends like you are super busy with the activities of life (like sports, homework, etc.). We’re REALLY happy when you guys get the chance to learn with us in Wonderopolis, too! Thank you for being such an AWESOME Wonder Friend…we appreciate you stopping by today’s Wonder! :-)

  12. Hello wonderopolis. I have never liked your videos and I don’t like this video. It’s so weird. Don’t get this video, so why do people cry?

    • Happy Wednesday, Aleia! We appreciate your opinion of the video we chose for today’s Wonder! Sometimes we choose videos that explain the Wonder of the Day® more or work to make us think a little bit or Wonder creatively. Sometimes we choose videos that simply show kids (and adults) something fun related to that Wonder’s topic…like today’s video does! :-)

    • Thanks for hanging out in Wonderopolis with us today, buglover! We’re glad you liked the video for today’s Wonder! :-)

  13. Great video guys. I thought it was cute! I really enjoyed learning more about a running nose!

    • Hello, Betsy! It’s SUPER AWESOME to hear from you! Thanks for letting us know you liked the video for today’s Wonder…we thought the stop-motion animation was pretty cool! We appreciate you being a WONDERful Wonder Friend and we hope you have a STELLAR week! :-)

  14. Today’s Wonderopolis is awesome! Do you have any wonders about video games or technology? How do I put a picture up next to where it says WONDERman? P.S. That video had some good stop action animation.

    • Happy Wednesday, WONDERman! We’re super happy that you liked today’s Wonder! Right now, we don’t have the ability to let Wonder Friends post pictures, but we will keep that in mind for the future! It ROCKS that you love technology! Check out all the great Wonders in our TECHNOLOGY category:

      Once you click on the link above, you can scroll down to see and explore as many Wonders as you like. You can also use the navigation arrows at the bottom of each page to explore even MORE! Happy WONDERing! :-)

  15. Hey Wonderopolis, remember me? So, I love you guys. I’M A HUGE Wonderopolis FAN!! Do you happen to have any for hockey (ice hockey). Wonderopolis, we use a loooottttt of technology! Hey, why don’t you have a tweet with my teacher Mrs.Thiessen or vist our class blog: and have a look around. Do you you guys have a blog? Where do you guys live? (country? state? province and city? )I live in Canada,BC,Vancouver.
    Sincerely, Mushkale

    • WOW, Mushkale! Thanks for leaving us such an AMAZING comment! It makes our day to know that you and your classmates are such big fans of Wonderopolis! We think Mrs. Thiessen ROCKS, too! Did you know that we already tweet with her? She shares lots of interesting information, and lets us know when you guys do WONDERful things in class! We already knew about your class blog, too, because Mrs. Thiessen is super proud of her students and wants everyone to know it! :-)

      Although we don’t have a Wonder specifically about hockey yet, a little Wonder birdie told us there might be one coming up in the future. Did you have a chance to visit the past Wonders we shared with you in our comment reply on Wonder #521
      Can You Speak in Code? If you didn’t, that’s OK…here they are again:

      Wonder #109 – What Is a Zamboni®?
      Wonder #67 – When Were Ice Skates Invented?

      Oh, and we live in Wonderopolis! :-)

    • Hi, Gracie! We’re glad you thought the video for this Wonder of the Day® was funny! Thanks for letting us know that! :-)

  16. Who knew mucus and noses could be so interesting? Runny noses are very annoying, but now we know how it happens. But it is kinda gross!

    • Hi there, Ms. Shultz’s third grade class! Learning about mucus and runny noses can be a little gross to some Wonder Friends, but sometimes learning about gross things is FUN! Thank you for visiting this Wonder and learning together today! We hope you all have the best day ever! :-)

  17. I don’t mean to be rude, but I have to do five projects each year on wonderopolis and I need your response for the project but, I do my project every morning and I never have your response in time so can you make response time earlier especially on the wonder of the day because those are the ones everyone likes.

    • Thanks for sharing your comment with us today, Wowgirl! We appreciate your concern! We try our best to answer every comment that comes to us in a timely manner. There are LOTS of Wonder Friends who leave us comments on the current day’s Wonder, but we also receive comments from Wonder Friends who like exploring some of our 570+ past Wonders, too! We try to answer each comment that we receive in the order we receive it. We appreciate that you like learning in Wonderopolis, and want to say THANKS for being a Wonder Friend! :-)

    • You bet, Mushkale! Thank YOU for being such a SUPER Wonder Friend! We really appreciate the way you WONDER! :-)

    • We like that question a lot, Maika! Did you know that many of the ideas for Wonders of the Day come from the creative, WONDERing minds of Wonder Friends just like YOU? It’s true! You can tell us what you are wondering anytime you like by leaving us a comment or by clicking on the “nominate” button at the top of every page in Wonderopolis! It’s fun and super easy! :-)

    • That’s really SUPER, Monica! Thanks for your kind words! Wonderopolis is a “10” of a place to learn new things…we’re glad you liked exploring this Wonder of the Day®! :-)

    • We really appreciate hearing that, Mushkale! Thank you for sharing your comment with us…we think all those smiley faces are AWESOME! :-)

    • We’re glad you visited Wonderopolis today, Gracie! Thanks so much for being a Wonder Friend and letting us know you liked this Wonder of the Day®! :-)

    • Thanks for letting us know you liked the music from this Wonder video, Claire! We really appreciate the GREAT comments you left for us all over Wonderopolis today! :-)

    • Sinus problems can be quite pesky, Jeff, but we’re glad to hear you’re doing great! Allergies can be annoying, but thanks to technology and helpful doctors, we can do our best to stop that runny nose! :)

  18. I never knew that the thing that was running down your nose was mucus.
    I also never knew that If your nose does start to get irritated, you might have to sneeze to expel the harmful invaders.
    I wonder how you had the idea to make that hilarious video?
    How did you think of this topic?

    • Hi Clark #20! Thanks for WONDERing with us! It’s easy to WONDER when you just look at the world around you! Keep WONDERing! :)

  19. I always thought the mucus was snot or is that the same thing? But i learned a lot like how doctors use a fancy word for “runny nose” which is “rhinorrhea”, I also learned that my body makes a quart of mucus every single day! I mean i knew my stomach made mucus to keep the acid from burning my stomach but i didn’t know that my body made mucus a quart a day! Thank you so much for the amazing lessons, you always keep me fascinated, Amazing job and thank you again for all you’re hard work and time. :D

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Have you ever wondered…

  • How fast can a nose run?
  • What is mucus?
  • What causes runny noses?

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toddler blowing nose_shutterstock_17738524Vimeo Video

Try It Out

If you have a runny nose, chances are you’re using plenty of tissues. Did you know that you can also make fun art projects with those tissues? It’s true!

Grab a friend or family member and a box of tissues and try out some of the fun art projects below:

When you’re finished, share your creations with the rest of your Wonder Friends. Post a picture on Facebook and feel free to share a story or two about how much fun you had. We can’t wait to see what you make!


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Pollen may make your allergies flare up, but some insects rely upon pollen. Check out Science NetLinks’ Dances with Bees lesson to learn about how honeybees communicate with sophisticated “dances” to tell other bees where to find nectar and pollen.


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