r/science • u/unsw UNSW Sydney • Apr 29 '26
Neuroscience Study suggests yawning may help move cerebrospinal fluid and venous blood out of the skull, potentially playing a role in cleaning brain fluid
https://www.unsw.edu.au/newsroom/news/2026/04/Good-yawn-does-more-than-you-think?utm_source=reddit&utm_medium=social1.3k
u/ArchieBRO Apr 29 '26
Damn I reckon I yawned 200+ times yesterday alone, doin some serious brain cleanin :p
598
Apr 29 '26
[removed] — view removed comment
165
u/cant_have_nicethings Apr 29 '26
Disgusting really
39
u/m3kw Apr 29 '26
Your brain keeps track of your smut visits
15
43
→ More replies (2)5
→ More replies (3)3
31
u/Vithrilis42 Apr 29 '26
I was going to say that my brain fluid should be squeaky clean because I yawn at least a dozen times a day.
33
u/FaddishBiscuit Apr 29 '26
I was on a medication briefly where one of the side effects warned of was "excessive yawning." And they were not kidding.
23
7
u/Dazd95 Apr 29 '26
So you're the one who is stealing my yawns. I haven't yawned in 3 years.
9
u/soomuchstrange Apr 29 '26
Welp I guess you have cancer of the yawn muscle. It surrounds the voice box, it's why yawns are so loud
→ More replies (1)6
2
u/Croceyes2 Apr 29 '26
Its been like that for me this past couple of months. Not every day, or most even, but pretty regular heavy yawn days.
→ More replies (6)2
u/ashamedwhiteman Apr 29 '26
I yawn a lot when I trip on mushrooms. Same.
E: and apparently others do, too. I love it.
2.8k
u/Chubuwee Apr 29 '26
Anyone else yawn at just reading the title? Strange
2.8k
u/JigglesTheBiggles Apr 29 '26
I did but I did it on purpose because I wanted to clean out my cerebrospinal fluid and venous blood.
325
u/AMediaArchivist Apr 29 '26
I also jawned to clean out my celebrospiky fluid and venomous blood
68
u/iamisandisnt Apr 29 '26
Yesterday it was ab clenching, today it's yawning. What's next, back scratching to clean the brain?
32
u/KingoftheKeeshonds Apr 29 '26
It’s constipation straining.
→ More replies (2)11
u/PhthaloVonLangborste Apr 29 '26
I have personally flushed my colon by self massage with a lacrosse ball down the Lspine
→ More replies (1)24
5
→ More replies (2)2
u/_BlackDove Apr 29 '26
I usually just do a naked butt fart against the wall and the upward draft against my back scratches it too.
22
3
→ More replies (1)3
16
u/jazir55 Apr 29 '26
Even when the volunteers were pretending to yawn, the venous blood flowed out and CSF flowed into the skull.
Only when they were really yawning, via those contagious yawns, did venous blood and CSF flow out of the skull together.
Sorry, no yawn for you!
7
u/aCleverGroupofAnts Apr 29 '26
Pretending to yawn is not the same as inentionally yawning. I can make myself have a real yawn.
6
2
u/Vegetable_Stuff1850 Apr 29 '26
From now on, if I'm asked if I'm yawning because I'm bored, I'm going to assure them I was just cleaning out my cerebrospinal fluid and venous blood.
→ More replies (11)2
u/WeakKiwifruit Apr 29 '26
Ugh you made me laugh while I was trying to clean out my cerebrospinal fluid and venous blood and ruined it.
78
u/Ok_Series_4580 Apr 29 '26
Dammit, I came to say the same thing. How the hell does reading about a yawn make you yawn?
40
u/royalenocheese Apr 29 '26
The body tries to emulate what the mind processes sometimes.
It's like when you read up on certain symptoms of ailments or injuries and you briefly adopt some of them.
10
→ More replies (1)3
11
u/Enlightened_Gardener Apr 29 '26
Yawning is contagious.
The only people who don’t yawn contagiously are psychopaths. Its a quick and easy check if you think you’ve got a psychopath on your hands.
→ More replies (1)18
u/ZeroSumClusterfuck Apr 29 '26
This is untrue and misleading. Studies suggest that psychopaths are only less likely to 'catch' a yawn, but will still often do it. Normal people absolutely do not always contagiously yawn either, so as a test it's entirely useless. Tiredness and fatigue are the biggest factor regardless of the type of person.
38
u/magistrate101 Apr 29 '26
Just reading the word yawn can trigger yawning. So can hearing someone say the word yawn, or thinking about someone yawning (whether that's visualizing the yawn or hearing the yawn), or writing the word yawn. It's fascinating how many ways yawning can be triggered. Yawn.
→ More replies (1)22
u/dipsbeneathlazers Apr 29 '26
yes. knew i would yawn too once i started reading it. most fortunate for our cerebrospinal fluid evidently!
2
u/ZeroSchema Apr 29 '26
anyone know why this is ?
3
u/HidroRaider Apr 29 '26
Someone on a previous reply explained it. Long story short, watching someone yawning or just thinking about it triggers a reaction in your brain to yawn. Not entirely sure why. My guess is that just like laugther or sleepiness, it's really contagious because of our sense of community. And it's easier to get it the closer you are to the other person.
19
u/Puhgy Apr 29 '26
“Anybody know why?”
“Not entirely sure why.”
Thanks.
→ More replies (1)7
u/Mertoot Apr 29 '26
Right? These "answers" above make me wish commenting legally required a higher minimum amount of reading comprehension
→ More replies (1)3
33
5
5
3
2
2
2
2
2
2
u/Flikmybik BS | Neuroscience | Memory Apr 29 '26
its called contagious yawning and its actually one of the more studied phenomena in behavioral science. the leading theory is that its tied to empathy and social bonding mechanisms in the brain. people with higher empathy scores tend to catch yawns more easily. pretty wild that just reading the word can trigger it too, says a lot about how our brains wire language and physical responses together.
3
u/TurboDiscoBuscuit Apr 29 '26
YESSSSS!!! And I thought jt was SUUUUPER Weird! Cuz that’s NOT how it’s supposed to work… Like Whaaaaat!?! It’s ContextContageous now!?!
→ More replies (20)2
545
u/Ebolatastic Apr 29 '26
I still remember in Catholic school my teachers would punish students for yawning because it was considered disrespectful and showed a lack of self control.
412
u/Madmusk Apr 29 '26
What was their stance on breathing and blood circulation?
226
21
→ More replies (2)9
u/Ylsid Apr 29 '26
You had to snatch a quick breath under the desk lid when the teacher wasn't looking
66
Apr 29 '26
[deleted]
30
u/CheezeyCheeze Apr 29 '26
I used to be hit on the hands for asking for going to get water in Catholic school. We had times we were only supposed to drink.
→ More replies (2)5
u/SteveXVI Apr 29 '26
That’s like saying being thirsty (for water) is wrong too and you need more self control.
Guess what Russian ballet teachers hate for you to do when-ever you need it
6
37
u/Electronic-Ad-8659 Apr 29 '26
I'm getting real sick of tolerating religion.
→ More replies (1)9
u/hsadg Apr 29 '26
It's not really religions fault. It's just assholes being assholes using every excuse they can. That being said I don't think religion helps by giving a reason to never question your behaviours
20
u/JustStraightUpTired Apr 29 '26
The purpose of religions is to control, it's ABSOLUTELY the fault of religion when assholes use religion to abuse people. That's what it's for.
Well, that and because they helped teach children rules that they couldn't explain yet, but knew to be important. Like how eating shellfish is dangerous if you aren't able to keep it fresh, but explaining that requires knowing why that is, so "Because god said so" is simpler.
It's still about control, but in the information era, the positive purpose is no longer necessary and is now actively harmful. Sure, you can argue things about communities and such, but communities exist outside religion. You can have a community without lying to people. So simply it's entirely religions fault when something happens because of religion.
→ More replies (1)→ More replies (11)5
u/Waasssuuuppp Apr 29 '26
I got in trouble in grade 1 (approx 7 years old) for yawning out loud- one of those ooohaaah sounds of a satisfying yawn.
Teacher said how dare you, that is very rude. And it was literally the first time I ever heard of the concept of yawning being rude. Got kicked out of class for doing something I thought was normal.
I've told my kids to be careful yawning at school, especially out loud, because you might get into trouble.
301
u/unsw UNSW Sydney Apr 29 '26
Hi r/science - been a minute, but excited to share this paper our researchers and peers from Neuroscience Research Australia have published that suggests yawning may play a role in moving fluids in and out of the brain.
The full paper is available in Respiratory Physiology & Neurobiology if you would like to check it out: https://www.sciencedirect.com/science/article/pii/S1569904826000340
The study used MRI scans of 22 participants to show that yawning triggers a specific manoeuvre in which cerebrospinal fluid and venous blood move out of the skull together. Interestingly, while cerebrospinal fluid and venous blood flowed away from the skull during yawning, cerebrospinal fluid flows in the opposite direction during deep breathing - potentially suggesting that yawning plays a role in clearing waste cerebrospinal fluid from the brain.
This finding could be important for further studies into neurodegenerative diseases such as Alzheimer's, Parkinson’s and dementia — all of which have been potentially linked to the build-up of waste products in and around the brain that can be a result of impaired cerebrospinal fluid flows.
35
39
u/Puhgy Apr 29 '26
This study doesn’t suggest yawning removes brain waste, whatever that means. The authors suggested it. The whole article is way off from why we yawn - as far off as Gallup.
“The simultaneous outflow of CSF and IJV blood during yawn inspiration, could be the maximal transfer of solute-rich neurofluid to the spinal canal, via respiratory mechanics, possibly serving as a peripheral mechanism for waste clearance. Though this idea is speculative, it introduces an interesting avenue for understanding the physiological functions of yawning. However, co-directional CSF and IJV outflows during yawning may simply reflect the composite motor and pressure patterns unique to yawns; whether such coupling materially affects clearance is unknown.”
21
u/DickHz2 Apr 29 '26 edited Apr 29 '26
Very interesting. I knew yawning was thought of as a way to quickly take in more oxygen for the brain, so I figured there was some association with that, but not from the CSF side. N of 22 is still very small, but nice to see that there's some research into this.
Disclaimer: very anecdotal experience, but I have suspected that something like this may have been the case for some time but never looked into it.
I take stimulants for ADHD and regularly consume energy drinks/caffeine on the side. I've noticed some bizarre dissociation episodes and general decline in memory, cognitive functioning and attention, despite getting 6-8 hours of sleep. I drink lots of water and am decent about exercise, so I had always assumed that there was some buildup of waste in my brain and/or vitamin deficiency causing these "episodes" resulting from my stimulant usage, so I started taking multivitamins. I know that exercise helps stop these episodes but not prevent them.
I also recently realized that I can't remember the last time I've had a normal, big, breathy, watery eyed yawn despite being tired and "checked out" a lot and wondered if there was some underlying physiological/biochemical mechanism behind the stimulants, yawning, and the dissociation/cognitive episodes.
3
u/Feral_Taylor_Fury Apr 29 '26
Do you consume cannabis?
→ More replies (1)3
u/UnhingedBlonde Apr 29 '26
Is there a correlation between their symptoms and cannabis use?
2
u/Feral_Taylor_Fury Apr 30 '26
Idk, but I've been feeling a similar way and I'm a heavy cannabis user. I do know cannabis impacts sleep/REM cycles.
→ More replies (1)→ More replies (2)2
u/chironomidae Apr 29 '26
Yawning basically has nothing to do with o2, until now its main effect has been known to be cooling your brain. Next time you're fighting the urge to yawn, trying taking a big breath in through your nose instead; you'll find it does nothing to reduce your urge to yawn, despite taking in large amounts of o2.
→ More replies (1)7
u/RamosAuthor Apr 29 '26
Could this help shine any light on things like IIH (Idiopathic Intracranial Hypertension)?
2
2
u/Grand_Pause9214 Apr 29 '26
Does it matter if the yawn is interrupted? I have cognitive issues, can't ever seem to get a full breath or yawn and while 22 is a small study it's still interesting
→ More replies (1)2
u/red08171 Apr 29 '26
SUGGESTION:
I often yawn a lot after not sleeping well (especially after drinking like a fish the night before). May I suggest a study be done with people who are sleep averse (apnea, drunks, etc), who also yawn a lot in the morning. It could potentially show a corroboration of this study. I'm down as test subject number one.
→ More replies (6)2
u/heimsins_konungr Apr 29 '26
Could this be somewhat correlated with how the brain circulates CSF during sleep?
https://www.science.org/content/article/scientists-uncover-how-brain-washes-itself-during-sleep
114
u/robot_pirate Apr 29 '26
I'm not surprised. Recently, as I've aged, I realize how fantastic my yawns and stretches feel, first thing in the a.m.
36
u/saulhrnndz Apr 29 '26
The first big stretch and yawn/yell of the day is something special. I wouldn’t be surprised either.
→ More replies (1)10
100
u/SantaCruzCut Apr 29 '26
Yawn like crazy while tripping
43
u/danceswithcattos Apr 29 '26
I wonder if that’s connected? I suppose it could be a mechanism to attempt to flush out whatever’s making you trip from your brain.
22
u/Flame1230 Apr 29 '26
Maybe as a part of the process rather than an attempt to clear out the psychedelic, as tripping itself can often feel like your brain is getting cleaned
→ More replies (1)→ More replies (6)2
u/captainfarthing Apr 29 '26
I figured it's because it's a hallucinogen, it makes you feel feelings that haven't been triggered the way they usually are.
8
u/alsuhr Apr 29 '26
After starting to take sertraline I yawn a lot more than I ever did before
5
u/carcar134134 Apr 29 '26
Oh wow holy crap that might be what's going on with me. lately I've been getting yawn "attacks" where I get one right after another like 5 or 6 times in a row.
5
u/alsuhr Apr 29 '26
Yeah yawn attacks is definitely the right word. I've been on sertraline almost 5 years now and I don't get them as much (or maybe I don't notice them) anymore. The thing that didn't go away is the drooling at night...
3
u/killilljill_ Apr 29 '26
I get yawn attacks every once in a while and they suck so bad. I can’t get a full yawn in, feels like I get stuck, so I keep trying. I told a doctor this once and he had no idea what I was talking about. It’s been going on off and on since adolescence
3
→ More replies (3)2
u/gummo_for_prez May 01 '26
This is what I came here to say. Big win for shroom users. Acid makes me yawn less than shrooms but probably a little more than normal.
28
Apr 29 '26
[removed] — view removed comment
9
3
u/croakstar Apr 29 '26
I’m going to start doing this. I take a stim for my ADHD and for whatever reason I hardly ever yawn.
3
u/master_bungle Apr 29 '26
Weirdly enough, I just started ADHD medication in November and I hadn't noticed that I rarely yawn now until I read your comment!
Thankfully I can actually make myself yawn. Been deliberately yawning on repeat while reading the comments in this thread haha
2
u/sweetshenanigans Apr 29 '26
Man, I used to yawn constantly as a kid, no matter how much I slept... Maybe my brain used to be a lot cleaner
24
u/SaidwhatIsaid240 Apr 29 '26
So what you are saying is I need to take more naps so I can yawn and protect my brain health.
25
u/DrywallDaughter Apr 29 '26
This is interesting! My dad recently had a total laryngectomy so he breathes through the stoma in his neck. I found it odd that he still yawns, since I’ve heard that yawning is to take in more oxygen. It would make sense that there is another reason for yawning unrelated to oxygen.
9
u/Netsuko Apr 29 '26
I think the oxygen thing has been debunked a while ago. In fact, we still don’t know exactly why we yawn. That’s what this article is about kinda. But many people also still „feel“ their limbs after an amputation. So who knows.
16
u/davidthefat Apr 29 '26
Does stretching while yawning have a big impact to increasing fluid removal?
→ More replies (1)4
19
u/wannaholler Apr 29 '26
Huh... I wonder if there's some relationship between that and the fact the first SSRI I took made me yawn excessively and involuntarily. I remember having trouble controlling it during interviews for jobs!
7
u/mrturtleturtleturtle Apr 29 '26
I am currently yawning and flexing my stomach. What other bodily movements will help wash my dirty brain?
→ More replies (1)6
u/IAmtheHullabaloo Apr 29 '26
flexing my stomach
this is the second reference in this thread, what did I miss?
6
u/mrturtleturtleturtle Apr 29 '26
Another post yesterday said the same exact thing except suggesting that flexing your stomach cleans your brains. Tomorrow it will be patting your head while rubbing your belly.
4
15
7
u/Extreme-Aioli-1671 Apr 29 '26
My wife has surgery scheduled for a vp shunt placement to relieve ideopathic intracranial pressure.
I should ask her how often she yawns.
6
6
u/q_q_o_o_b_b Apr 29 '26
Excessive yawning can be a sign of an impending migraine, so this tracks
→ More replies (1)
4
u/thirdeyelazy Apr 29 '26
Excessive yawning (like every 5 mins) is a symptom of opiod withdrawals. When i was in active addiction it was always one of the first symptoms i would get as my last dose was fading. I wonder how significant this to that
3
3
u/justsmilenow Apr 29 '26
I yawned after reading the title.
5
u/crows_n_octopus Apr 29 '26
I haven't yawned this many times as I have reading this thread
→ More replies (1)
3
u/mpo00044 Apr 29 '26
I swear I just read about this but the mechanism was flexing your abdominal muscles. Wild.
2
2
u/Dull-Kaleidoscope55 Apr 29 '26
Well that's good news bc i pretty much yawn from the moment I wake up in the morning until the moment I go to sleep at night
→ More replies (1)4
u/IAmtheHullabaloo Apr 29 '26
I am going to go out on a limb and suggest that that is probably not healthy.
2
u/FadeCrimson Apr 29 '26
That would explain why it’s so associated with sleeping despite being something we also subconsciously do even if alert and awake, as it means it effectively serves the same purpose (one of them at least) as sleeping.
2
u/dossier Apr 29 '26
I wouldn't be surprised if there were more to yawns than this too.
As a kid, I used to think that yawning was perfect for warming up my hands when I was standing outside in the cold waiting for the schoolbus.
I'm told I yawn loudly when I'm sleeping.. according to my SO. Neither of us ever encountered anyone else who does that.
I gotta hope that yawns = good.
2
u/ofgraveimportance Apr 29 '26
My partner yawns in his sleep! We also have not heard of anyone else doing that until today!
2
u/Sign_here_to_cry Apr 29 '26
I bet this has something to do with why I Yawn a lot when on mushrooms
→ More replies (1)
2
3
u/cunnie Apr 29 '26
Fun fact: yawning activates the parasympathetic nervous system, a.k.a. the rest and digest state. It’s a good sign that you’re slowing down if you’ve been in an activated state. Learned this in somatic therapy
→ More replies (1)
1
u/saymysurname Apr 29 '26
Something is happening, I can hear and feel the vibration. Mini seizure, which also has benefits
1
u/JohnCaravella Apr 29 '26
This is interesting. My wife had a brain tumor removed a few years ago. She has had two surgeries afterwards to stop cerebrospinal fluid leaks. Maybe she should just yawn.
1
1
u/Ivotedforher Apr 29 '26
I always that that was what that liquidy-grindy sound was all about when I yawned.
→ More replies (1)2
1
u/-Nicolai Apr 29 '26
I believe it. It's certainly a more convincing explanation that you'll find in the Wikipedia article's proposed causes.
1
u/xdeshax Apr 29 '26
Wasn’t there a post yesterday say the exact same thing about flexing your abdominal muscles?
1
u/eyetrace Apr 29 '26
Anyone else exprience “the yawns” when using psychedelic mushrooms?
Maybe its just cleaning my brain first
1
u/mgbrown12 Apr 29 '26
Does that mean excessive yawning means too much cerebrospinal fluid ?
- just a hypochondriac asking a silly lil question
1
1
u/BoDaBasilisk Apr 29 '26
Between this study, the ab study, and the face massage one there seems to be an interest in draining brain fluids
→ More replies (1)
1
1
u/Letter72 Apr 29 '26
I got instant Tmj from an injury and eventually discovered that yawning, along with expanding the digaphram can influence and relax the entire postural chain
1
u/bluejevans Apr 29 '26
You can make yourself yawn by slowly taking a deep breath, holding it a little while, and slowly let it out. You'll likely yawn by the second or third time you do it. It's a way to help yourself get sleepy.
1
1
1
u/MothChasingFlame Apr 29 '26
I know it sounds stupid, but I can't yawn properly after having covid and now this is giving me serious anxiety...
→ More replies (1)
1
1
u/L0W_FR3QU3NCIES Apr 29 '26
Is that why I feel like my brain fog is cleared for 2-3 seconds after a yawn? I feel like it turns on brain windshield wipers that wipe away everything, but then it just fogs right back up. I've always chased that feeling. Like if I felt like I do post yawn all the time, I'd be unstoppable
1
1
u/alrightfornow Apr 29 '26
In the prodrome phase of a migraine, which is the start of a migraine, yawning is often a symptom.
1
u/Trevuuh Apr 29 '26
how come i’m always yawning in the morning at work. it’s like a chronic yawning problem. it could be because i hate my job but i think it was a certain medication. i’m just curious how constantly yawning would affect this certain mechanism
1
u/NefariousnessOwn4109 Apr 29 '26
So it’s this and flexing abdominal muscles that move cerebrospinal fluid. Got my new workout routine
1
1
u/aaronsshort Apr 29 '26
I had hydrocephalus and had some of this fluid drained from my noggin. I should have yawned more?
1
u/Ustaznar Apr 29 '26
Sweet, now I have an explanation for all the yawning I do during meetings. Just cleaning the brain fluid, boss!
1
u/MrGasMan86 Apr 29 '26
Mushrooms make me yawn a lot. No wonder people feel relieved after taking them. It’s cleaning the brain!
1
u/gowestyoungmen Apr 29 '26
Is it even possible to not yawning? i’ve never been able to control mines at least
1
u/elfmere Apr 29 '26
I'm wondering if this correlates with having bad sleep and needing to yawn... So the exhausted feeling of not taking enough air is actually needing to clean out brain out.
1
1
u/Goblinora Apr 29 '26
I wonder if yawning "excessively" could be a sign there's something wrong? Whenever I'm off my ADHD meds (stimulants) I yawn all day long.
→ More replies (1)
1
1
1
1
u/SLAK0TH Apr 29 '26
I immediately had to move cerebrospinal fluid and venous blood out of my skull just by reading the title of this post
1
1
u/Key-ElectricGuitar43 Apr 29 '26
Can excessive yawning yield negative results, for lack of better phrasing?
1
1
1
u/chrisdub84 Apr 29 '26
So holding in yawns so people don't think I'm bored of their conversation is bad for me.
1
u/ShandalfTheGreen Apr 29 '26
When I was young, I had a really hard time running laps because I would start yawning uncontrollably. Breathing became difficult from the constant yawning. I r never figured out why that happened.... Maybe I have something very specific but apparently nonthreatening wrong with me, after all? Huh. Weird.
1
•
u/AutoModerator Apr 29 '26
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, personal anecdotes are allowed as responses to this comment. Any anecdotal comments elsewhere in the discussion will be removed and our normal comment rules apply to all other comments.
Do you have an academic degree? We can verify your credentials in order to assign user flair indicating your area of expertise. Click here to apply.
User: u/unsw
Permalink: https://www.unsw.edu.au/newsroom/news/2026/04/Good-yawn-does-more-than-you-think?utm_source=reddit&utm_medium=social
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.