Wendie Trubow, MD, MBA, IFMCPPresident at Five Journeys, Functional Medicine & Wellness Provider, Best Selling Author, Passionate Champion for Health

Nose vs Mouth Breathing What It’s Doing to Your Body

27 May 2026 · 1 min

Watch on YouTube

0:39

In this brief explanatory segment, Dr. Wendie Trubow describes how the development of the jaws determines whether a person breathes primarily through the nose or the mouth. Well‑developed jaws allow unobstructed nasal airflow, while under‑developed jaws restrict nasal passage, prompting the brain to automatically open the mouth to secure adequate oxygen. This mouth‑opening is an involuntary reflex, not a conscious choice. The shift to chronic mouth breathing can degrade health, notably by impairing sleep quality.

Chapters

The difference between nose and mouth breathing oftentimes is the jaw growth and development. When the jaws are well developed, we breathe through our nose easily. But when the jaws are not well developed, it makes it harder to breathe through the nose. And that's when the brain kind of takes over and makes a choice. Well, you're not really breathing through your nose very well. I think I'll help you. And that's when it opens your mouth. So opening the mouth is not like a conscious thing that you do, thinking it through. Like, you know, my nose isn't— my nose is not open and breathing well. I will open my mouth today and walk around like this. It's an automatic thing. When your brain realizes that the air's not flowing through your nose well, it separates your lips. Then you're mouth breathing. And next thing you know, we're unhealthy because it affects the sleeping quality.