As far as bodily functions go, good ol’ breathing is probably one you don’t think about very often. You may assume everyone takes in oxygen through their nose, but some people default to breathing through the mouth. And that simple fact makes a big difference.
Why: Mouth breathing can lead you to over-breathe (seriously!), messing up your oxygen and carbon dioxide balance. And it’s been linked to sleep apnea, which nose breathing can improve. (More details on how later.) So doing it all through the nostrils is ideal, says pulmonologist Jamie Garfield, MD.
Ahead, experts settle the nose-versus-mouth debate—and share how to perfect the practice.
You get cleaner air through your nose
The hairs in your snout strip out allergens and pollutants, making sure fewer ickies end up in the lungs. But the mouth doesn’t have a filter system. “It is really for eating and talking, not breathing,” says Dr. Garfield.
Need more motivation? Your lungs and throat thrive on warm, moist air, and the nasal cavity has built-in structures that heat up and humidify air in a way your mouth can’t. Also, nasal breathing just takes less energy because it relies on the diaphragm, the largest respiratory muscle in the body.
Nasal breathing can help you sleep more deeply
Nitric oxide, which improves blood flow and makes it easier for your lungs to pick up oxygen, is produced via the sinuses. So, when you take in air through your nose, you help reduce your risk for sleep apnea (when your breathing repeatedly stops and restarts in the night), Dr. Garfield says. Longer and slower breaths (only possible through the nose) activate your parasympathetic nervous system, helping your bod chill; mouth breathing, in contrast, triggers a fight-or-flight response. Dry mouth, bad breath, and snoring are signs your breathing is sabotaging your shut-eye.
You can train yourself to nose-breathe
If you don’t have a breathing issue (like a deviated septum), try this: Breathe in, then blow air out (both through the nose) and don’t breathe until you have to. Or try alternating nostrils: Close one as you inhale, then the other as you exhale. Practice these exercises throughout the day to increase your likelihood of doing it during sleep, says Rebecca Robbins, PhD, an instructor in medicine at Harvard. No need to use mouth tape, despite what you’ve seen on social media—there’s no proof it solidifies the habit any better.
This article first appeared in Women's Health US in April 2023.