The SNEEZE.

Jan 10 2011 Published by under Basic Science Posts

The other night, Sci was drifting slowly off to sleep.  Suddenly, I sneezed.  It woke me up completely again, and left me wondering, with some irritation, whether it couldn't have waited til I was asleep and didn't care.

And then I thought: CAN you sneeze in your sleep? I asked the Twitterverse and looked around in vain. There are conflicting reports. I may not ever have my answer.

But dang did I ever learn a lot about sneezing. And of course, when that happens...I gotta blog it. So today's post is going to be a basic science post (SCIENCE! 101) on the SNEEZE. How it works, what causes it, and...whether you can do it in your sleep.

ResearchBlogging.org Songu and Cingi. "Sneeze reflex: facts and fiction" Therapeutic Advances in Respiratory Disease, 2009.

(Props go out to Songu and Cingi, who have written what may very well be one of the most entertaining reviews I have EVER read. I highly recommend).

Is there anything better than sneezing kittens?

Maybe sneezing baby elephants.

The sneeze (the medical term is "steternation") is a respiratory reflex, a series of stereotyped movements which follow from each other in their entirety. Once you complete the inhale portion of a sneeze, you're going to complete the rest of it, the only thing you can control is how loudly and where it goes.

A sneeze can be divided into two sections, the sensitive phase, and the efferent (outward) or respiratory phase. The sensitive phase is the stimulation in your nose, the tickle that says that something is coming. This is the point at which you can try to stop it with a finger under your nose or something and you may very well be successful. The tickling sensation in your nose is the result of stimulation of the trigeminal nerve. This is the 5th cranial nerve (out of 12, I really HAVE to do a post or 12 on the cranial nerves some day...always so much to blog!), and it extends out and innervates the skin of your face, including the delicate mucosa inside your nose.


(That's your trigeminal nerve. All over your FACE. Source)

The trigeminal nerve sections inside your nose end in sensitive receptors. Some of these are sensitive to chemicals (think capsaicin), while others are sensitive to mechanical stimuli (which would be a physical particle like dust mechanically pressing against the receptor). When you get something in your nose or something stimulates the trigeminal nerve, the signals travel up toward the brain and hit the lateral medulla.


(look where the white arrow is pointing. Source)

This area is a sneezing center for you brain, and when stimulated enough, will trigger the reflexive response of a sneeze. If you have enough of a tickle in your nose, the lateral medulla will reach threshold, and send signals out to the lungs, eyes, and throat. And you get the following sequence.

1) Your eyes close (if your eyes don't close during a sneeze, you may not be going through the full stereotyped series, and this can be an indication in a patient that sneezing is the result of a psychiatric issue rather than a physical one).

2) You breathe in DEEP.

3) Your glottis (a series of fleshy folds in your throat) closes.

4) You breathe out explosively, building up pressure in the lungs, the glottis flashes open in response. Air exists rapidly through the mouth and nose.

ACHOOOOO.

5) You recover and start feeling around somewhat desperately for a kleenex.

There are lots of different causes of sneezing. The most common are things like the common cold and allergies (rhinitis), and the photic sneeze reflex (called ACHOO syndrome, which I have blogged about before, and which is sneezing in response to sudden exposure to bright light). But there are other, less well known causes of sneezing, some of which are pretty amazing.

- physical stimulation of the trigeminal nerve: this can be a feather, dust up your nose, or a good whiff of capsaicin.

- central nervous system pathologies. The big one here is called lateral medullary syndrome. Sneezing isn't a symptom here, it's actually a cause! The onset of LMS has been associated with a massive onset of sneezing, which can shear the vertebral artery and prevent blood from getting to the lateral medulla, causing a whole hose of very unpleasant symptoms, one of which is that the person CANNOT sneeze following that initial outburst. Other pathologies which can have sneezing as part of their symptoms include types of epilepsy, where sometimes sneezing can predict the onset of a seizure.

- psychogenic sneezing: this is the type of sneezing I mentioned before, where someone sneezes and sneezes and cannot appear to stop, but the sneezes are small, and the eyes often stay open. These sneezing fits (a case report of one was 2 months in duration) respond best to talk and behavioral therapy.

- snatiation reflex: this is a fun one! This is a rare condition in which people sneeze when their stomachs are FULL. "Snatiation" is apparently the combination of "sneeze" and "satiation", and otherwise stands for the acronym "Sneezing noncontrollably at a tune of indulgence of the appetite- a train inherited and ordained to be named" aka "medical students really need to find better ways to amuse themselves". It's extremely rare, but really does happen.

- sneezing at sexual ideation or orgasm. This was a totally new one to me. With regard to noses and orgasm, the only thing I've ever seen before is that characters in Japanese anime shows seem to get nosebleeds when they think sexy thoughts (would love to know the physiological basis behind that one).

This is, of course, completely mythical. But there ARE people who SNEEZE when exposed to sexy thoughts. It's pretty rare, but sneezing and sexual excitement has been documented since the 19th century. People used to think that maybe this was because both erections and sneezes were the results of blood flowing to "erectile tissue" in the penis and nose respectively, but now we just don't know. There are case reports both of people sneezing immediately following orgasm, as well as reports of people who sneeze merely at the thought of hotness. It's very rare, but if this DOES happen to you, I think you might want to keep it to yourself, otherwise every time you sneeze your friends will look at you funny.

But there is one important thing about sneezing. You know how your mother or friends told you not to hold in your sneezes because your face would explode or something (I was told my eyes would pop out)? Well, your eyes won't pop out and your face won't explode. But the pressure involved in a sneeze IS up to 176mmHg IF you are closing your nose. And that's a bit. It's enough to cause damage to things like your hearing and your eyes, and even caused a woman with osteoporosis to break her nose. So let your sneeze fly proud!

And now we come to the final question: CAN you sneeze in your sleep? Well, I still don't know. But here's how I think of it.

Concepts FOR sneezing in your sleep: it's a reflex and should occur automatically, though it might then wake you up.

Concepts AGAINST sneezing in your sleep: there's a condition that most people enter in to when asleep wherein you lose most of your muscle tone (this happens in non-REM sleep, it's not sleep paralysis, that's different). This might prevent you from sneezing, and might be a GOOD thing, because then you won't, you know, accidentally bite your tongue in half or something.

So, does anyone know which it is? And can give me a citation? Sci's gotta have DATA. My current hypothesis is that we probably CAN sneeze in our sleep, and the muscle tone relaxation prevents us from biting our tongues in half anyway, but what do I know?

But for now, Sci's going to sleep. Hope I don't sneeze.

Songu, M., & Cingi, C. (2009). Sneeze reflex: facts and fiction Therapeutic Advances in Respiratory Disease, 3 (3), 131-141 DOI: 10.1177/1753465809340571

39 responses so far

  • Gerty-Z says:

    ARGH! Now this is driving me insane! I did a Pubmed search--nothing. But I did find that, according to Indiana Public Media, you can NOT sneeze in your sleep. http://indianapublicmedia.org/amomentofscience/sleep-on-sneeze-not/. But no data!! Booo!

    • scicurious says:

      Yeah I see loads of docs and media outlets and stuff saying you can't sneeze in your sleep, but no one ever cites ANYTHING.

  • Ed Yong says:

    So what factors determine the loudness of a sneeze? Why is it that some people I know literally say "Achoo" really quietly, while at my quietest, I can bring down small planes?

  • liz says:

    A great blog post! Both my brother and my father (and my paternal grandmother, while she was still alive) have huge sneezing fits after eating too much, and I've always wondered why. I can now out-nerd them at our next family dinner by telling them about the lovely word 'snatiation'.

    Weirdly, my mum and I both have have ACHOO syndrome (photic sneeze reflex) - I occasionally amuse myself by thinking about the effects of our entire family eating a large dinner in a brightly-lit room.

    Liz

  • Pharm Sci Grad says:

    Anecdote: my dentist, when diagnosing me with TMJ (which I woke up with one morning) claimed it was probably due to yawning and sneezing simultaneously in my sleep.
    It doesn't quite clear my bullshit meter today, but apparently he thought it was possible...

    • scicurious says:

      I gotta say my BS meter pinged over that one. TMJ CAN be caused by grinding of the teeth in your sleep, which I think would be more likely.

  • anonymous says:

    My wife CAN sneeze while she's asleep. I've seen it a handful of times - and she clearly doesn't wake up or remember it. So hopefully that answers your question.. On the other hand, she has the ability to sleep through air planes taking off and landing and once managed to sleep nearly 18 hours out of 24 on a long road trip, so my guess is that it is simply a rare talent.

  • I sometimes sneeze when my dentist is cleaning my teeth, particularly when he is working on the front uppers. He told me that this is very common in dental patients.

  • becca says:

    The sneezing panda is in my top 10 favorite youtube videos of all time. Right behind "here it goes again".

    ZOMG! liz! What if snatiation has a genetic basis? experiments must be done!!!!!
    Do any animals sneeze if they get too full? FAT RAT experiments must be done!!!!! /geekout

  • "Snatiation" would make an excellent band name. =)

  • liz says:

    @becca haha yes! I for one would love to conduct detailed genetic experiments on my whole family. I'm totally with you on this geekout :)

  • Kate says:

    Good stuff, thanks!
    But could you please change "psychiatric" to "psychological" in the phrase "sneezing is the result of a psychiatric issue"? Psychiatry might be the applicable treatment, or it might not. Conditions aren't in themselves psychiatric.

  • I could quote you a poem about someone who has it the other way around - experiences sexual stimulation induced by sneezing. The poem (by Maureen Sexton) is fiction, and hardly the best poem ever written, but it's the first thing I thought of. Here's a taste (verse 5 of 6):

    Through the night as passion seizes,
    dust clouds billow around her bed.
    And she welcomes icy breezes!

  • aimee says:

    I read, "The SNEEZE" and immediately wondered if my hubby's little affliction would be addressed. LOL, it was! He's a sexual sneezer. Like clockwork, it occurs about 1:30 into foreplay every time we have sex...unless we're in the shower. Hmmmmm...

    Of course, I like to give him a hard time when he sneezes randomly.

  • cj dunn says:

    Well, I have had two complaints the past few days about me sneezing in my sleep. I have no recollection of it, strange

  • tari says:

    I use to have the pleasure of sneezing but now I don't what's that all about . And have slight pressure on my right side of head. Ever heard of this issue.

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  • Dom says:

    My son began to sneeze in his sleep about 2 months ago and it's been almost every night since. It never wakes him up though, hmm.. I thought it was normal, but maybe I should go see an allergies! Thanks!

  • Camille says:

    I sneeze when full, and at 62 have never met or known of anybody tht does. It's weird because people think you're pulling their leg. And laugh in disbelief. Lol

    • Kris says:

      I am almost 40 and I go through the same thing. Especially when I got to lunch with my co-workers. It can sometimes get pretty embarasing. I have gone to Dr.'s and the ysend me to an alergy specialist and they find out exactly what I told them, Im not alergic to anything. Im almost relieved and happy to finely see that I am not the only one who goes through this.

  • levi says:

    "The sneeze (the medical term is "steternation") is a respiratory reflex"

    Sternutation >>> is the correct spelling. didn't know if you just missed it or you didn't know how to spell it. I don't mean to be a drag about it, but you might want to change the spelling. Many people may refer to your work, and then that will make them sound like an idiot because they quoted you. I do like the research you did, however I didnt finish the article because I'm writing a fiction novel. -Thanks

  • Lesa says:

    My husband and son both sneeze uncontrollably arfter eating a large meal.
    We have found ice to help greatly. When they feel like they are gonna start sneezing,
    we get an ice cube. They hold it in their mouth. Sometimes it stops
    the attack. Sometimes shortens it. Strangely holding ice in hand and mouth
    at same time seems to work best....try it. Wish a doc could explain this one...

  • Michelle says:

    My 8 year old son sneezes in his sleep (2-3 minute sneezing fits) and does not wake up. Even when I try to wipe his nose. I have not talked to his doctor yet, but plan to.

  • Hazel says:

    http://today.msnbc.msn.com/id/35814608/ns/today-today_health/t/bless-you-girl-who-kept-sneezing-has-stopped/#.UIYBvm_Mhfx

    this girl!

    She keeps sneezing, but she stops sneezing when she sleeps.
    autoimmune condition though.

  • Cho says:

    My son sneezes EVERY single night when he is sleeping. It is a running joke in our family. When he sneezes, when know he is in his deep sleep. "*SNEEZE* *SNEEZE*. He's sleeping now!" EVERY night since he was an infant....I always thought it was weird, kind of funny weird. I mentioned it to my pediatrician once, but he dismissed it and said he had never heard of such a thing. I think he thought I was just making it up. We went to an ENT today, and she also said she had never heard of it. He is having a sleep study done soon, so maybe we'll get some answers.

    • Shorty says:

      Hey let me know what happens, I'm curious because my Mom has been sneezing in her sleep for the past 2 or three years now in her sleep , it wakes me up because I'm a light sleeper,the thing is, that she doesn't know she was sneezing in her sleep until recently when it started to wake her up. I don't know if this helps, but when she was younger,(shes 49) shes used 2 have massive nosebleeds due to weak capillaries....

  • Elisa says:

    I've read at internet that is impossible to sneeze while sleeping. For me, it isn't right. I've lost count of the times I've woke up after a powerful sneeze, always scaring myself in despair right after, not understand what happend. Once, somebody taught me how to sleep in the best position to the column. Also, she said that positiong would keep action in my abdomen, as with I woke up, I could easly start to run... I was praticing it when, one night, deeply asleep, dreaming, the sneeze came. All that action kept in my muscles made me almost fly of the bed. I was so scared and so confused that by the time I realised what happend, I was at the other side of the room.

  • Clara says:

    Sneezing most diffidently occurs in your sleep. I don't have the science to back it up but it has been the reason I have been woken at around 3 am every morning this week. I was looking for reasons why when I can across this site. I wake up around the second sneeze and continue sneezing for another 4 or five times. Then is stops and I am wide awake.
    If anyone knows any reasons for this please let me know. Kind of getting irritating.

  • Missy says:

    Sneezing not only happens when I'm full after eating, it happens when I drink more than two or three cups of water. Anything that fills the stomach to the point that it hits that "sneeze nerve"( as I've always called it), will do it...food, water, beer, etc. My eyes water, my sinuses fill with mucus, and I can sneeze 10 to 15 times and have to blow and blow my nose....totally aggravating! In 60 years, no doctor has EVER been able to tell me what causes this...thought they all took anatomy in med school. They all have said allergies, until I tell them drinking water will trigger this condition....who's allergic to water!? No one else in my family has this, so I don't know about any genetic connection. It is an automatic portion controller for sure, you can't enjoy eating once the sneezing and sinus congestion start, because like when you have a cold, you can't taste the food. After a lifetime of this, I still think it's weird, but I am happy to see I'm not the only one with it!

    • Deb says:

      I'm guessing that the "sneezing when full" syndrome isn't that uncommon. My father always suffered from it, and for all of my life, I have too. What's interesting to me is that my daughter's husband also has the same problem. I'm watching my grandson (their first child) closely to see if he will be doomed to a double genetic dose of it since clearly, my son-in-law and I are not related by blood.

  • Tina says:

    My son most definately sneezes in his sleep and it wakes ME up. That is how I stumbled ontk this site... I was doing a search since I couldn't fall back to sleep. I feel that he is not getting restful sleep because of it. I need more info.

    • Jennifer says:

      I have been going through the same thing and wondering if he's ok. He'll be sleeping and then have a sneezing fit. I guess it's somewhat normal if its happening to other kids too. I do plan on mentioning it to his doctor though.

  • Shauna says:

    My boyfriend occasionally sneezes in his sleep. Doesn't wake &doenst remember.i have a sneezing problem. Someone stopped me from sneezing & now I can't pretty much unless I'm not around anyone? I'd say I miss out on about 75% of my sneezes now?

  • Beth says:

    I have the Snatiation sneezing. Mine isn't hereditary. It never happened until after I had gastric by-pass surgery. I use it as a gauge to when to stop eating. I think sneezing is sexually related as well. My nipples always get hard after sneezing.

  • Mom says:

    My daughter sneezes in her sleep 5-7 times in a row almost every night.

  • Mel says:

    My son had just sneezed in his sleep, which is why I looked it up! I thought he was awake again (he's only 5).

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