1. During wakefulness, you have conscious control of your breathing rate and volume. Breathing volume and patterns are also altered by environmental factors such as anxiety, exercise, talking or resting.  Behavioral influences include things like yawning, sighing, and laughing, also alter breathing patterns and volume of breathing which are constantly in play to maintain a regular breathing pattern.

    

2. During sleep, your breathing rate and volume are controlled and adjusted by the breathing control center of the brain. This is where the critical difference between nose breathing vs mouth breathing becomes apparent. Sleep breathing is significantly affected by nose vs mouth breathing. Nose breathing reduces the airflow disturbances caused by mouth breathing and prevents the collapse of the airway. The primary breathing muscles are the upper airway muscles, the diaphragm (inspiration) and the abdominal muscles (during expiration). Of the various breathing muscles, the upper airway muscles appear to be the most dramatically affected by changes occurring with sleep. These muscles have reduced function during sleep.

    

3. During NREM sleep, the breathing pattern is more regular than wakeful breathing. During REM sleep (about 4 to 5 occurrences during sleep), the breathing pattern is characterized by an increased rate and reduced regularity. Also, there are more sleep arousals triggered by the brain to correct major interruptions in the airflow through the upper airway. These interruptions are far more common with mouth breathing, which is why understanding nose breathing vs mouth breathing is essential for minimizing sleep disruptions.

    

4. Studies consistently demonstrate during REM sleep there are more sleep-related reductions in muscle activity of the upper airway than of the diaphragm or accessory muscles of respirations. This reduced muscle activity occurs during REM sleep. Skeletal muscles associated with breathing are significantly impaired and ventilation is accomplished by the diaphragm alone. During this vulnerable phase when airway muscles are relaxed, nose breathing vs mouth breathing makes an even more dramatic difference in maintaining open airways.

    

5. Positional changes during sleep affect the mechanics of breathing significantly. Anatomic structures of the upper airways may be more predisposed to collapse, particularly with the concurrent reductions in upper-airway muscle tone. This is significantly increased in the supine position (back sleeping).

Why Nose Breathing Vs Mouth Breathing Matters for Sleep Quality

Now that you understand how your breathing changes when you sleep, let's look at why the choice between nose breathing vs mouth breathing is so critical:

Benefits of Nose Breathing During Sleep:

• Maintains open airways – Nasal breathing reduces turbulence and prevents airway collapse
• Filters and humidifies air – Protects lungs and respiratory system
• Produces nitric oxide – Enhances oxygen delivery to tissues
• Reduces sleep disruptions – Fewer arousals from breathing interruptions
• Supports deeper REM sleep – When airways stay stable
• Prevents snoring – By maintaining proper airflow patterns

Drawbacks of Mouth Breathing During Sleep:

• Increases airway collapse risk – Especially during vulnerable REM sleep
• Creates turbulent airflow – Leading to snoring and sleep disruptions
• Dries out airways – Causing inflammation and discomfort
• Triggers more sleep arousals – As brain corrects breathing interruptions
• Reduces sleep quality – Preventing deep, restorative rest
• Leaves you feeling unrested – Despite adequate sleep hours

The Connection: Wake Up Energized by Choosing Nose Breathing

When you understand does your breathing change when you sleep and why nose breathing vs mouth breathing matters so much, you can make a simple change that transforms your mornings. People who breathe nasally during sleep consistently report that they wake up energized, while mouth breathers often wake up feeling groggy, with dry mouth, and lacking energy.

The difference? Nose breathers experience: More time in deep, restorative sleep cycles – Because their breathing doesn't trigger arousals

• Better oxygenation throughout the night – Thanks to nitric oxide production
• Fewer micro-awakenings – Leading to more consolidated sleep
• Stable airways during REM sleep – The most critical phase for restoration

When you wake up energized, it's not just about getting enough hours—it's about the quality of those hours. And quality sleep starts with how you breathe.

Bottom Line: Nose Breathing Vs Mouth Breathing for Optimal Sleep

So, does your breathing change when you sleep? Absolutely—and those changes make the choice between nose breathing vs mouth breathing even more critical than during wakefulness.

Bottom line - it is helpful to nose breathe during sleep while sleeping on your side. Additionally, it is helpful to practice calm, regular breathing with diaphragm function during wakefulness to mimic that of NREM sleep, the predominate breathing cycle. Using mouth tape for sleep can help ensure you maintain nose breathing throughout the night, supporting better sleep quality and respiratory function.

When you prioritize nose breathing vs mouth breathing during sleep—especially by using mouth tape designed for comfort and safety like Simply Breathe—you set yourself up to wake up energized, restored, and ready to take on the day. The science is clear: how your breathing changes when you sleep matters, and maintaining nasal breathing throughout the night is key to deep, restorative rest.

Reference: v. Malik, et al. “Respiratory Physiology During Sleep.” Sleep Med Clin 7 (2012) 497-505