What I've Learned About Mouth Breathing In Children
“No other species breathes as poorly as we do.” — James Nestor, Breath
When I first started questioning my child’s sleep and behaviour I was constantly told things like:
“Snoring is normal.”
“He’ll grow out of it.”
“You’re overthinking it.”
But something didn’t sit right.
Then I listened to James Nestor’s interview on The Diary of a CEO podcast with
Steven Bartlett and subsequently read his bookBreathand suddenly, it all started making sense.
What if the root of so many of my child’s struggles wasn’t “just how kids are,” but something more basic?
Something as simple as how he was breathing.
This post is everything I wish I’d known sooner and everything Nestor taught me that is now reshaping the way I parent, advocate, and show up for my child.
Mouth Breathing Triggers the Stress Response System
“Mouth breathing… elicits a stress response in the body, increasing cortisol and blood pressure.” — Breath, p. 47
Mouth breathing doesn’t just look a bit off. It actually shifts the body into a state of chronic stress. It activates the sympathetic nervous system, which is responsible for our fight-or-flight response.
In kids, this can show up as:
Restlessness during sleep
Frequent bedwetting
Tantrums or anxiety-like behaviours
Difficulty concentrating
Trouble staying calm or emotionally regulated
It’s no wonder many kids with these symptoms are misdiagnosed or medicated, when in reality, their nervous system might simply be overstimulated by the way they’re breathing.
The Nose Is a Built-In Air Filter
“The nose is more than a simple air passageway—it’s our first line of immune defence.” — Breath, p. 47
The nose isn’t just for smelling. It filters air, warms it, humidifies it, and produces nitric oxide (a gas that helps deliver oxygen deeper into the lungs and bloodstream.) According to Nestor on DOAC, this leads to 18% better oxygen uptake compared to mouth breathing.
Nasal breathing helps:
Strengthen immunity
Improve sleep quality
Regulate mood and energy
Support brain function and memory
Reduce the risk of infections
If your child always seems tired or foggy, breathing through the nose could make a bigger difference than you'd think. By breathing through their mouth, chances are they’re not getting the levels of oxygen they should be.
How We Breathe Shapes the Face
“The human mouth is shrinking. The bones in our faces are growing smaller and our teeth no longer fit.” — Breath, p. 79
This one hit me like a ton of bricks. Nestor dives into the link between mouth breathing and facial development, especially in growing children.
Narrow palates.
Crowded teeth.
Elongated faces.
Recessed jaws.
In his book, Nestor undergoes an experiment where he blocks his nose for 10 days and sees his snoring increase by 4,820%, his blood pressure spike, and his health decline rapidly (DOAC episode). If just 10 days did that to an adult, imagine what years of mouth breathing can do to a developing child.
Here’s a little graphic I put together to help visualise a mouth breathing child:
Snoring in Kids Is NOT Normal
“Snoring is not just a loud annoyance—it’s often a sign of disordered breathing.” — Breath, p. 201
We normalise snoring in children way too much. But Nestor is clear: it’s not cute, and it’s not harmless. It’s a warning sign.
In fact, when I showed the doctor videos on my child snoring, mouth wide open, having apnea episodes, he was unconcerned. He told me it’s normal, and even smirked as though it was slightly endearing. I knew he was wrong.
If your child:
Snores or grinds their teeth
Sleeps with their mouth open
Wakes up tired despite 10+ hours of sleep
Struggles with focus or behaviour during the day
It may be disordered breathing.
On Diary of a CEO, Nestor pointed out that we medicate kids for attention problems without asking how well their brain is being oxygenated while they sleep. That hit me hard.
Modern Life Is Working Against Healthy Breathing
“We’ve become the worst breathers in the animal kingdom—and it’s largely our own doing.” — Breath, p. 20
The modern world isn’t designed with airway health in mind and unfortunately, many everyday habits and conveniences are quietly compromising our children’s ability to breathe well.
For example:
Soft, processed diets mean children aren’t chewing enough to stimulate proper jaw development, which can narrow the airway and affect palate formation.
Bottle-feeding and prolonged dummy use can alter tongue posture and facial growth, particularly when not balanced with breastfeeding or early weaning practices.
Chronic allergies and congestion (made worse by poor indoor air quality and rising pollution levels) often lead to blocked noses so kids adapt by mouth breathing.
Screen time encourages forward head posture and slack facial muscles both of which interfere with correct oral posture and nasal breathing.
Even sleeping environments, like overly warm rooms or lack of proper elevation, can contribute to snoring and mouth breathing at night.
None of these factors on their own are to blame. But together, they create a perfect storm, especially during those crucial early years when your child’s face, airway, and breathing patterns are developing.
This isn’t about guilt. We’re all doing the best we can with the information we have.
But awareness changes everything. Once you start seeing the connection between these habits and your child’s breathing, you can begin to make small but powerful changes. Ones that support healthier development, better sleep, and stronger foundations for life.
What This Has Meant for My Family
I wish I could say that once I learned all this, everything changed overnight. But the truth is, we’re still very much on this journey.
We’ve made progress:
My son now has a hearing aid to help with hearing reduction linked to glue ear (after over a year of being dismissed)
We’ve started making small changes to the home environment and daily habits.
We’re asking better questions, seeing new specialists, and pushing back when needed.
But there are still unknowns.
Still long waits.
And, every night I listen powerlessly to my 5 year old take frequent pauses and gasps in his sleep.
The difference is, I’m no longer doing this blind. I no longer feel like I’m overreacting. And I’m no longer waiting to be told he’s bad enough to take seriously.
This knowledge has become a compass. And it's helped me trust myself again as a mother.
I hope you’ll find value in it too!
Tasha x
“We can’t always change the world, but we can change the way we breathe in it.” — James Nestor
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I’ll be sharing more on how we’re navigating airway health, from referrals and sleep studies to home changes, red flags, and the professionals who actually helped.
Our next stage is trying something called Myofunctional Therapy. We’ll be travelling to London late July to get started on what will be a 6-9 month treatment plan. The aim of it is to retrain him to breath through his nose. I’ll keep you posted.
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