Breathing is the most fundamental thing we do. It happens automatically, without thought, around 20,000 times every day. Yet most of us give virtually no attention to how we breathe. The reality is that how you breathe — through your nose or through your mouth — has profound implications for your sleep quality, energy levels, and overall health.
As The Sleep Ambassador®, I’ve spent years studying the connection between breathing and sleep. What I’ve learned from leading researchers, physicians, and my own work with clients has fundamentally changed how I think about this most basic human function.
We Were Designed to Breathe Through Our Nose
Your nose is not just a passageway for air. It’s a sophisticated filtration, warming, and humidification system. When you breathe through your nose:
- Air is filtered of dust, allergens, and pollutants by nasal hairs and mucus
- Air is warmed to body temperature before reaching your lungs
- Air is humidified, preventing dryness in your airways
- Your body produces nitric oxide, a molecule that improves oxygen absorption, supports blood flow, and has antimicrobial properties
Mouth breathing bypasses all of these benefits. It delivers cold, unfiltered, dry air directly to your lungs and throat — and it’s the breathing pattern most commonly associated with snoring and poor sleep.
The Science Behind Nasal Breathing and Sleep
Research has established clear links between nasal breathing and sleep quality:
1. Reduced Snoring and Sleep Apnea
Nasal breathing keeps the tongue and soft palate in their proper position. When you mouth breathe, the jaw drops, the tongue falls back, and the airway narrows — creating the conditions for snoring and obstructive sleep apnea (OSA).
2. Better Oxygenation
Nitric oxide, produced during nasal breathing, opens blood vessels in the lungs and improves oxygen uptake by approximately 18%. This means more oxygen reaches your brain and body during sleep.
3. Parasympathetic Activation
Nasal breathing — particularly slow, controlled nasal breathing — activates the parasympathetic nervous system, which promotes relaxation and restful sleep. Mouth breathing, by contrast, tends to activate the sympathetic (fight-or-flight) system.
4. Improved Sleep Architecture
Studies have shown that nasal breathing supports deeper, more restorative sleep stages. Mouth breathing is associated with more frequent awakenings and lighter sleep.
Why So Many People Mouth Breathe
If nasal breathing is so clearly superior, why do so many people breathe through their mouth, especially during sleep? Common causes include:
- Nasal congestion from allergies, colds, or sinus issues
- A deviated septum that restricts airflow on one or both sides
- Enlarged tonsils or adenoids, particularly in children
- Habit — many people have simply developed the habit of mouth breathing over time
- Structural issues in the jaw, palate, or airway
The critical point is this: mouth breathing is not your body’s preferred mode. It’s a compensation for something blocking or compromising nasal breathing. Address the root cause, and you can restore the breathing pattern your body was designed for.
Practical Steps to Improve Nasal Breathing
1. Clear Nasal Obstruction
If congestion or a deviated septum is blocking your nasal breathing, address it. Nasal dilators like Mute can gently open nasal passages, providing immediate relief. For persistent issues, see an ENT for evaluation.
2. Practice Nasal Breathing During the Day
Conscious nasal breathing during waking hours retrains your body’s default pattern. Simply close your mouth, place your tongue gently on the roof of your mouth, and breathe slowly through your nose. Over time, this becomes your default — even during sleep.
3. Try Breathing Exercises
Controlled breathing practices like alternate nostril breathing or extended exhale breathing strengthen nasal breathing habits and promote relaxation before bed.
4. Tape Your Mouth at Night (With Caution)
Some sleep specialists recommend mouth taping to encourage nasal breathing during sleep. If you try this, use specially designed sleep strips — never regular tape — and ensure you can breathe through your nose comfortably before attempting it.
5. Read James Nestor’s “Breath”
If you want to understand the profound impact of breathing on every aspect of health, Breath: The New Science of a Lost Art by James Nestor is essential reading. This book changed the conversation about breathing and will change how you think about every breath you take.
Breathing Is the Foundation of Sleep Health
In my work with corporations, athletes, and individuals, I always start with breathing. You can optimize your sleep environment, your schedule, and your habits — but if your breathing is compromised, your sleep will be too.
Take a moment right now: close your mouth, breathe in slowly through your nose, and exhale slowly through your nose. Notice the difference. That’s your body’s preferred way to breathe. Give it the chance to do what it was designed to do, especially during sleep.
For more on the science and practice of nasal breathing, read my article on Mute Snoring: Breathing As Designed.
By Nancy H. Rothstein, MBA, The Sleep Ambassador®