Nose vs mouth breathing: Which one is better for your health?

In 2004, a documentary called Supersize Me made quite a splash. In it, an independent filmmaker, Morgan Spurlock, committed to eating at McDonald’s for 30 days and documenting his experience. That experience wasn’t pleasant—he gained weight, became lethargic, developed high blood pressure, and had a host of other health issues. His takeaway was clear—eating a lot of fast food is not good for your health.

I was reminded of this film as I was reading a recently released book, Breath: The New Science of a Lost Art, by James Nestor. In it, among other things, the author documents his experience with a Stanford mouth breathing experiment. In this experiment, he was supposed to breathe exclusively through his mouth for ten days and then exclusively through his nose for the next ten days. His experience of breathing through the mouth was eerily similar to eating a lot of junk food. “After just 240 hours of breathing only through our mouths, catecholamine and stress-related hormones spiked, suggesting that our bodies were under physical and mental duress. […] All the while, my blood pressure was through the roof and my heart rate variability plummeted.” On top of that, his snoring increased 4820 percent from the beginning of the experiment, and he began to suffer from obstructive sleep apnea (that over time can lead to all sorts of health issues). He also experienced “nagging fatigue, irritation, testiness and anxiety”. (1) After switching back to nose breathing, all of those symptoms went away – his blood pressure dropped, heart rate normalized, he stopped snoring and having episodes of sleep apnea, his sinus infection cleared, his athletic performance improved, and he was feeling much better in general.

This experiment clearly demonstrated that breathing exclusively through the mouth has all sorts of consequences for our health. This is not surprising, since the mouth is supposed to be a backup option for when we cannot breathe through the nose, it was never meant as a primary breathing channel. There are many functions the nose performs that the mouth never could. Here is a short list of some of nose functions.

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1. Preparing air for the lungs

The lungs and throat do not tolerate dry air well. The nose processes the air we breathe to prepare it for our lungs. A mucous membrane rich with blood vessels lines the nasal cavity. The increased surface area and the many blood vessels enable the nose to warm and humidify incoming air quickly.

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2. Cleaning air of dirt and pathogens

The air we breathe has all kinds of foreign particles in it – dust, pollution, allergens, smoke, bacteria, viruses, small bugs, etc. Cells in the mucous membrane produce mucus and have tiny hairlike projections (cilia). The mucus traps incoming dirt and pathogens, and the cilia carries it out of the airway. This action helps clean the air before it goes to the lungs.

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3. Control of the air stream

The complicated labyrinth of valves and turbines within the nose regulates the direction and velocity of the air stream. This ensures maximum exposure to the fine arteries, veins and nerves, as well as the mucus blanket to clean, humidify, warm and smell the air.

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4. Olfaction (sense of smell)

The nose has a large number of nerve cells that detect odors. We sniff to pull in the air to come in contact with these nerves. Sense of smell is necessary for safety. We need our smell to detect smoke, spoiled food and some toxic gases. Smell is also intimately connected to taste; food will appear tasteless if the sense of smell is impaired.

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5. Nasal resistance

The nose creates a narrow passage for the air, which creates resistance for the air flow. This resistance is necessary to maintain elasticity of the lungs and to ensure proper ventilation. Nasal resistance also conditions the tissues on the back of the throat to prevent sagging (which can lead to snoring and obstructive sleep apnea).

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6. Nitric oxide production

The vasodilator gas nitric oxide (NO) is produced in the paranasal sinuses and is excreted continuously into the nasal airways. NO improves oxygen transport throughout the body and oxygen absorption in the lungs. It relaxes vascular smooth muscle and allows blood vessels to dilate. NO also has antifungal, antiviral, antiparasitic and antibacterial qualities.

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7. Nasal cycles and connection to autonomic nervous system

There is a predictable pattern of swelling and shrinkage within the nose that alternates airflow between two sides of the nose. It is called the “nasal cycle”. Nasal cycles are linked to sympathetic (SNS) and parasympathetic (PNS) nerves and impact body temperature, blood pressure, hormone production, arousal level and even mood.

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None of those functions are performed by the mouth, which means that if we breathe through the mouth (because of a habit or chronic congestion in the nose), we take in cold, dry air ridden with pathogens, forgo the benefits of nitric oxide and the rhythm of nasal cycles. On top of that, we end up changing the entire structure of our nasal cavity.

James Nestor writes: “Mouth-breathing, it turns out, changes the physical body and transforms airways, all for the worse. Inhaling air through the mouth decreases pressure, which causes the soft tissues in the back of the mouth to become loose and flex inward, creating less overall space and making breathing more difficult. Mouth-breathing begets more mouth-breathing. […]

Sleeping with an open mouth exacerbates these problems. Whenever we put our heads on a pillow, gravity pulls the soft tissues in the throat and tongue down, closing off the airway even more. After a while, our airways get conditioned to this position; snoring and sleep apnea become the new normal. […]

Inhaling from the nose has the opposite effect. It forces air against all those flabby tissues at the back of the throat, making the airways wider and breathing easier. After a while, these tissues and muscles get “toned” to stay in this opened and wide position. Nasal breathing begets more nasal breathing.”(1)

Why do we end up breathing through our mouths?

Mouth breathing usually starts because of nasal congestion, which occurs when nasal tissues and blood vessels become swollen with excess fluid. Usually, the congestion clears within a week or two, but a mouth-breathing habit remains. If you have severe allergies or congestion issues due to a deviated septum or other reasons, you would need medical advice and a tailored yoga practice designed specifically for your needs by a qualified yoga therapist.

What can we do about our mouth breathing habits?

First, you need to figure out if you chronically breathe though your mouth during one or more parts of your day: during exercise or yoga practice, during other daily activities, or at night.

If you find yourself breathing through your mouth during yoga or exercise, simply switch to your nose (if possible). You might need to dial down the intensity of your exercise at first while your body adjusts to the new way of breathing. Once it becomes natural, you can increase the intensity again. If your nose is too congested to be the primary pathway for airflow, you will need to work on clearing your congestion first (using some ideas below) and then work with conscious, simple breathing during your asana and pranayama practice.

If you find yourself resorting to mouth breathing often during the day, take time to notice if there is an actual need for it (because your nose is congested), or if it’s just a habit. If it’s a habit, you will need to keep reminding yourself to breathe through your nose. You can try the following tricks to make it easier for yourself:

• Couple your new pattern of nose breathing with specific activities (like walking, doing yoga, taking a shower, scrolling through your social media feed) to remind yourself to do it,
• Press your tongue upwards against your hard palate and keep it there at the roof of the mouth. Make it a habit – it’s harder to breathe through your mouth in this position,
• Speak slower and in shorter sentences, so that you don’t have to gasp air in between. Breathe through your nose when you speak.

If your nose is chronically congested, you could try some of the following things:

• Try neti pot irrigation. It involves pouring lightly salted water through each nostril every morning or at any point during the day. It often helps with clearing extra mucus from your nose.
• Chewing dense food instead of soft, mushy food for your meals helps to recondition the muscles of your face, mouth, and throat; it tones the soft tissues on the back of your mouth and opens airways.
• Practice simple nasal breathing during your yoga practice. Remember, nasal breathing begets nasal breathing. Be sure not to do intense or forceful breathing, as it can create too much pressure in your sinuses.

If you snore, sleep poorly, and wake up with a dry mouth, it might mean that you are breathing through your mouth at night. You cannot control your breathing pattern as easily at night as you can during the day. It might help to do a simple pranayama practice before bed and to sleep on your side. Another solution that James Nestor describes in his book, and I heard recommended by other yoga teachers and breathing therapists, is mouth taping. It involves placing a small strip of surgical tape across (or along) your lips to prevent your mouth from opening at night. Some folks swear by this technique and attribute dramatic changes in their health and energy levels to mouth taping. I never tried it myself, so I cannot advise it with certainty. But you can learn more about it in this video. Note of caution, though – please do not attempt mouth taping until you are absolutely certain that you can breathe comfortably through your nose at night.

We all benefit from closing our mouths and relearning to breathe through our noses at all times. For some, it will involve changing a habit, and for others, it will be a complex process of clearing out chronic nasal congestion. It might not be easy, but nose breathing is one of those foundational things that is definitely better for your health and is worth the effort.

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References and resources

1. Breath: The New Science of a Lost Art by James Nestor
2. Behavioral and Physiological Approaches to Breathing Disorders by R.Ley (Editor) and B.H. Timmons (Editor)
3. Restoring Prana by Robin Rothenberg