CW Vol 2 Ed. 33 - Mouth Breathing: The Overlooked Habit Sabotaging Your Health

Most of us don’t think twice about how we breathe. But according to dentist, author and sleep medicine advocate, Dr. Mark Burhenne and breathing expert Patrick McKeown, breathing through your mouth — even for part of the day or night — can quietly harm your oral health, your sleep, and your overall well being.

Why Mouth Breathing Is a Problem

When you breathe through your mouth instead of your nose:

• Your mouth dries out, lowering saliva flow.

• pH drops, favoring bacteria that cause cavities and gum disease.

• The oral microbiome — the community of bacteria that protect your teeth, gums, and even your heart — becomes imbalanced (“oral dysbiosis”).

• Your airway is more likely to collapse during sleep, worsening snoring and sleep apnea.

• You lose more moisture, leading to dehydration, fatigue, and brain fog.

“If the oral microbiome starts repopulating in a desiccated (dry) environment, it becomes more pathogenic (capable of causing disease.) You’re supporting the bugs that don’t like oxygen.” —Dr. Mark Burhenne, Ask the Dentist

Nighttime: The Hidden Danger Zone

Even people who breathe through their nose all day often switch to mouth breathing at night without realizing it. During sleep, saliva glands slow down, so an open mouth dries quickly — and that dryness can stick airway tissues together, increasing the chance of breathing interruptions.

Signs you might be mouth breathing at night include:

• Waking with a dry mouth or sore throat

• Morning headaches

• Frequent nighttime bathroom trips

• Snoring or restless sleep (ask your bed partner if you snore)

Why Nose Breathing Wins

Nose breathing:

• Filters and warms the air

• Maintains moisture and saliva levels

• Supports nitric oxide production, which helps regulate blood pressure and fight infections

• Keeps the oral microbiome balanced

What You Can Do

Check your nasal airway – If you can’t comfortably breathe through your nose for several minutes, address nasal congestion or structural issues first.

• Train yourself to nose breathe – During light activity, keep your mouth closed; this builds habit and strengthens your airway muscles.

• Consider safe mouth taping at night – Use only products designed for this purpose, and only if nasal breathing is clear and comfortable.

• Optimize your sleep environment – Improve bedroom ventilation or crack a window to keep CO₂ levels lower.

Quick Quiz: Are You a Mouth Breather?

Try these 3 simple self-checks from Dr. Mark Burhenne and Patrick McKeown:

• Morning Mouth Test: Wake up and notice — is your mouth dry or your throat scratchy? That’s a sign your mouth was open during sleep.

• Resting Breath Check: While sitting or standing still, close your mouth and breathe through your nose for 3 minutes. If it feels difficult or you switch back to your mouth, you may have nasal blockage or habit-related mouth breathing.

• Light Exercise Challenge: During a short walk or other light activity, keep your lips sealed. If you quickly feel “air hungry,” your nose breathing muscles and patterns need retraining.

Why it matters:

Nose breathing filters and warms air, supports healthy saliva flow, and helps keep blood pressure in check — mouth breathing doesn’t.

Learn More

Listen to the insightful conversation between Patrick McKeown and Dr. Mark Berhenne here.

Or watch on YouTube here.

Follow Dr. Mark Berhenne on IG @askthedentist or click here.

View this newsletter here.

8/13/2025