The science of nasal breathing
Most of us breathe through our mouths far more than we realise. Below, we look at how nasal breathing differs and what the published research does and doesn't show, and we say plainly where the evidence is strong and where it's limited.
Your nose does a lot that your mouth can't: it warms, filters and humidifies the air, and adds nitric oxide from the sinuses. When the nose is blocked or the nostrils collapse, people tend to switch to mouth breathing, especially at night. Researchers have looked at how that switch relates to snoring, sleep, the mouth, exercise, feeling calm, pregnancy and, in children, development.
What your nose does that your mouth can’t
Your nose does all of this on every breath, without you thinking about it.
A natural nitric-oxide boost
Your sinuses make nitric oxide, and breathing in through your nose carries it into your airways. In the body, it’s a molecule that helps blood vessels relax.
Nitric oxide, on every nasal breath
A calmer state
Research links slow, steady breathing with shifts in the body’s stress response, including heart-rate variability and a calmer feeling.
Linked with a calmer state
Built-in air filtering
Your nose warms, humidifies and filters air before it ever reaches your lungs, trapping dust, allergens and bacteria on the way in.
Cleaner air to your lungs
Steadier breathing
Nasal breathing tends to be slower and gentler, and some studies link it with more efficient breathing.
Steadier, more efficient breathing
Deeper, fuller breaths
Mouth breathing tends to be quicker and shallower. Breathing through your nose slows each breath down.
Slower, fuller breaths
Quieter nights
Sleeping with your mouth open raises airway resistance and makes snoring more likely. Keeping the nose open supports quieter breathing.
Quieter, easier breathing
Mouth breathing and snoring
Well studiedSleeping with the mouth open tends to narrow the airway and make snoring more likely. Studies that compare the oral and nasal breathing routes during sleep have found that breathing through the mouth raises upper-airway resistance, which is closely tied to snoring. When a blocked or narrow nose is part of the problem, keeping it open supports quieter breathing.
References
- Fitzpatrick MF et al. Effect of nasal or oral breathing route on upper airway resistance during sleep. Eur Respir J, 2003.
- Meurice JC et al. Effects of mouth opening on upper airway collapsibility in normal sleeping subjects. Am J Respir Crit Care Med, 1996.
Steadier breathing, steadier rest
Well studiedFragmented, open-mouth sleep means more time in a lighter, more alert state and less in calm, restorative rest. The same research on breathing route during sleep links open-mouth breathing with higher airway resistance and an airway that collapses more easily. Easier nasal breathing supports quieter, more settled rest, though it isn't a treatment for any medical sleep condition.
References
- Fitzpatrick MF et al. Effect of nasal or oral breathing route on upper airway resistance during sleep. Eur Respir J, 2003.
- Meurice JC et al. Effects of mouth opening on upper airway collapsibility in normal sleeping subjects. Am J Respir Crit Care Med, 1996.
Dry mouth overnight
Well documentedBreathing through an open mouth overnight dries up saliva, the mouth's natural defence for the teeth and gums. Research links habitual mouth breathing with reduced saliva and poorer oral-health markers. Nasal breathing helps keep the mouth more naturally moist.
References
- Mummolo S et al. Salivary markers and microbial flora in mouth breathing children. BioMed Research International, 2018.
- Wagaiyu EG, Ashley FP. Mouthbreathing, lip seal and on-going gingival inflammation. J Clin Periodontol, 1991.
Breathing efficiency when you train
Emerging evidenceMouth-only breathing tends to be quicker and shallower, a less efficient way to exchange air. Some studies link nasal breathing with better breathing efficiency and lower perceived effort. The evidence does not show that it boosts raw power or maximal oxygen uptake (VO₂max), so think of it as steadier, more comfortable breathing rather than a performance upgrade.
References
- Eser et al. Nasal vs oral breathing and ventilatory efficiency during exercise. Frontiers in Physiology, 2024.
- Recinto et al. Effects of nasal or oral breathing on anaerobic power output and metabolic responses. Int J Exercise Science, 2017.
Why steady sleep matters
Background contextPoor-quality, broken sleep keeps the body in a more alert state and means less time in calm, restorative rest. Over the long term, disrupted night-time breathing has been associated with higher blood pressure. The strong blood-pressure research below studied people with diagnosed obstructive sleep apnoea using CPAP therapy, not mouth breathing and not a nasal product. We include it only as general background on sleep and the heart.
References
- Martínez-García MA et al. Effect of CPAP on blood pressure in patients with OSA and resistant hypertension (HIPARCO). JAMA, 2013.
- Becker HF et al. Effect of nasal CPAP treatment on blood pressure in patients with OSA. Circulation, 2003.
Breathing and growing faces
Strong associationIn children especially, long-term mouth breathing has been associated in research with differences in how the jaw and face develop, including narrower jaws and longer face shapes. This is one of the better-studied associations in the field. It's general information, not a product claim. Airlift is not a children's product or a treatment, and any concern about a child's breathing or development should go to a healthcare professional.
References
- Zhao Z et al. Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis. BMC Oral Health, 2021.
- Zheng W et al. Facial morphological characteristics of mouth breathers vs nasal breathers: a meta-analysis. Experimental and Therapeutic Medicine, 2020.
Slow breathing and a calmer state
Background contextMany relaxation and breathing techniques are built on slow, steady breathing. Research links slow breathing with measurable shifts in the body's stress response, including heart-rate variability and self-reported calm. This is general information about slow, nasal breathing, not about Airlift, and it is not a treatment for any medical condition.
References
- Zaccaro A et al. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 2018.
- Ma X et al. The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Frontiers in Psychology, 2017.
A stuffy nose in pregnancy
Well documentedA blocked, stuffy nose is a common and well-documented part of pregnancy, often called pregnancy rhinitis, and it can disturb sleep. Because it's driven by hormonal changes, it usually settles after birth. A drug-free nasal dilator can make nose-breathing easier without sprays or medication, but this is general information, not medical advice, so check with your midwife or doctor.
References
- Ellegård EK. Pregnancy rhinitis. Immunology and Allergy Clinics of North America, 2006.
- Ellegård E, Karlsson G. Nasal congestion during pregnancy. Clinical Otolaryngology, 1999.
A simpler way to keep the nose open
Airlift is a reusable magnetic clip and skin-safe stickers that gently hold your nostrils open to encourage nasal breathing. There are no straps, and nothing goes up your nose.
This page is general information, not medical advice, and not a claim about what Airlift can do for you. Speak to a qualified healthcare professional about any concerns.