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Do you need to nose breathe more?

 •  • by Paul Ingraham
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Weekly nuggets of pain science news and insight, usually 100-300 words, with the occasional longer post. The blog is the “director’s commentary” on the core content of PainScience.com: a library of major articles and books about common painful problems and popular treatments. See the blog archives or updates for the whole site.

Any bodily function we have any control over at all is suspiciously in need of upgrades — according to gurus and folk wisdom. For instance, many people believe that more and better use of their noses for breathing will enhance… something. More relaxing, maybe. Warmer O2? Look, it’s just better, m’kay? Billions of people not examining their assumptions cannot possibly be wrong! (Except that they totally can, they do it all the time.)

The healing power of nostril breathing is one of those minor, casual claims that is just floating around out there in a low key way, something almost everyone keen on their health and fitness has heard of… but few people take seriously, or examine critically. But Dr. Harriet Hall did. She recently wrote about this oddball claim for ScienceBasedMedicine.org, which is why it’s on my mind. She examine the nostril-breathing subspecies “in through the nose, out through the mouth”:

“We breathe in oxygen and breathe out carbon dioxide without having to think about it. But many people tell us we should think about it. … I couldn’t find any scientific evidence to support the common advice to breathe in through the nose, out through the mouth.”

In this post, I’ll add some of my own nosey thoughts so far — just one step on a longer journey to a major new deep dive into breathing, relaxation and meditation (which I expect to publish in about 7 weeks, or maybe 37).

Close up of a golden retriever’s nose.

With any of these health & fitness rituals that are supposedly good for us, it’s always worth noting that other animals don’t do them.

The basics as benefits

I can’t find a clear notion of the bloody point of deliberately doing extra nose breathing, in any particular way. Don’t most people mostly breathe through their noses already? And yet good luck getting through any yoga class without being told to do it.

The only plausible benefits I’ve seen are almost comically elementary and unimportant. Even credible sources casually conflate the basic physiological functions of the nose with the “benefits” of nostril breathing. Yes, your beautifully evolved schnoz will indeed warm, humidify, and partially filter your air — which is a bit less irritating to the rest of the respiratory system than cold. Congratulations, you’re an animal with a functional respiratory tract, which includes two breathing holes that we quite naturally use as needed, for different reasons at different times.

I doubt that biology allows us to significantly screw that up through inattention. None of the standard features of noses means that anyone needs to emphasize nostril breathing.

There’s always relaxation, of course — more on that below.

That’s the carrot, now for the stick: is mouth breathing dangerous?

Every health ritual these days has both touted benefits to attract you to it… and a bogeyman to spook you into it. This is a strong pattern because fear sells . In the case of nostril breathing, the scare story is that too much mouth breathing is actually hazardous. But that is unlikely. Excessive mouth-breathing might be a sign of other medical problems, but it’s probably not in itself the cause of anything scary.

There is a prominent claim that excessive mouth-breathing is an underestimated sign of surprisingly serious underlying pathologies, which can have serious long-term consequences, especially in children. This may or may not be true. Certainly many conditions can partially block the nasal passages, acutely or chronically, and you will mouth-breathe if you cannot nose-breath, but most of them are obvious. Are there ominous and underestimated causes of mouth breathing? Even if there are, even if it’s not just hyperbolic fear-mongering… then the mouth breathing is just a symptom of a medical problem, not a “bad habit” that is sickening otherwise healthy humans.

And yet that is exactly how it is framed by many sources! Too many of them are all too happy to argue (or just let people assume) that mouth breathing itself is dangerous. Which, I submit, is definitely hyperbolic fear-mongering. Case in point…

Nostril breathing to keep your teeth straight?

This is a good example of a bad justification for recommending more nostril breathing. It’s bizarre and muddled. I wouldn’t normally give an idea this weak so much air time, but I found this garbage claim at the very top of the Google search results for “breathing in through the nose and out through the mouth”:

Breathing through a person’s nose helps the facial muscles and bones develop correctly and helps develop straight teeth. When the mouth is closed, the tongue is in the proper position to help the jaw grow correctly, and teeth emerge in the right places.

That is why you “must” breathe through your nose? For twenty years while your face is still growing? This is gibberish (as was most of the article). With really kooky claims like this, I’m always torn about whether I should earnestly spell out my objections, or just roll my eyes at it. In this case, it seems so dumb that it doesn’t deserve actual analysis.

But… it’s at the top of the search results for the topic! Despite Google’s constant efforts to keep low quality information out of their search results. Well done, Google. •golf clap•

The point is that people have come up with many imaginative and frightful ideas about why would should nose breathe. Most them, I suspect, are just hand-waving speculation that emerged well after the original popularization of nostril breathing… which was almost certainly thanks to yoga and meditation classes.

It’s the pranayama, stupid

The nostril-breathing fandom is probably mostly about pranayama, or yogic breathing exercises. And that means the spirit of the thing is roughly equal parts…

  1. Vitalism, the belief in an animating life energy, like The Force in Star Wars. And vitalism is entirely a toxic ideological dumpster fire.
  2. A mash-up of both ancient Eastern and modern New Age folk medicine wisdom. And all that is mostly silly garbage (but always with some wholesome basics to fend off lazy skeptics).

The classic pranayama idea is that we breathe with the left nostril to relax (“cooling, liberating”), and the right to get revved up (“heat generating”). This much more specific claim is straight out of pranayama (yogic breathing exercises), and probably nowhere else. And it seems seems testable! And it has been tested! With predictable results. A 2022 paper compared left and right nostril breathing, and found that they were both slightly relaxing — all parasympathetic, no sympathetic regulation from the right side, no heat generated.

That was a study done by Indians, and I have a hunch that they were probably disappointed by that result. If they couldn’t p-hack their way to a bias-confirming result, who can?

I suspect that alternate-nostril breathing has been simplified for mass consumption to just “in the through nose, out through the mouth” — but basically still right out of yoga and meditation. And it may also just be another idea from pranayama (there were a bunch of them, after all).

Photo of a woman in fitness clothes, sitting on a yoga mat, pouring herself a glass of wine. The caption reads: “To relieve stress I do yoga. Just kidding, I drink wine in my yoga pants.

Good yoga can be great. But, hoo boy, yoga has also produced a great deal of nonsense.

What about just relaxation?

Many of the stranger ideas in health and fitness and alternative medicine are often not very appealing to ordinary folks, who aren’t always interested in paying for chakra-tickling. And so such ideas are almost always made more palatable for the mass market by using bland and secular backup claims like “and it’s relaxing” and “whatever else it does, at least it increases circulation!”

Boring benefit bullet points are critical to the marketing of virtually all health nonsense. (See also above re: “basics as benefits.”) Their presence is a red flag.

In the case of nostril breathing, I think “boring benefits” are probably the whole enchilada. There is no step two.

Slow, deep, and deliberate breathing exercises probably are somewhat relaxing, for whatever that is worth (not nothing, but maybe less than you think — that’s another topic I’m working on). But I doubt that nostrils have much to do with it, except that it is probably a good way of getting you to slow down.

If nostril breathing has any legitimacy as a health ritual, then it would have to be because some kind of nostril breathing is clearly more sedative than other respiratory patterns.

I was not able to find any science about this whatsoever. As far as I know, it’s just never been tested. Probably because no one serious actually cares — and that is how it goes with most lightweight folk medicine claims.

All nostrils, all the time? Even while sprinting?!

I have occasionally encountered the idea that we should only breathe through the nose … even during intense aerobic respiration, when you are most likely to need to guzzle air at a much higher rate than usual. I have actually seen people make this argument. It would be entertaining to watch them try to play some soccer or run 10 kilometres without breathing through their mouths.

I have no idea where this nonsense comes from; to me, it has the ring of typical muddled modern health guru BS.

Personally, I prefer to breathe like a dog: enthusiastically! Through whatever damned holes naturally suits me at the time.