It felt like every part of my life improved after a recent nasal surgery, from my allergies to my mental health. That may not be a coincidence. Nose breathing is a superpower hidden on the front of your face.

For as long as I can remember, each breath felt like preparing for a swim underwater, a hard suck of air that never quite filled my lungs. Often I'd walk around with a faint whistle in my nose, praying that no one could hear it. The worst problem was a minor disability that most people refused to believe was real: something about the cruel architecture of my face made it physically impossible to blow my nose. The world was a constant sniffle.

Life cursed me with a deviated septum. My right nostril was blocked on the best of days, and I'd wind up breathing through my mouth at the slightest hint of allergies. The nasal troubles even contributed to my sleep apnoea, a breathing condition that makes you wake up multiple times at night, which apparently leaves you more likely to die of any cause. But after decades of unpleasantness, my doctor suggested surgery. The plan was to straighten my septum and reduce my turbinates – bony structures covered in a mucous membrane that condition the air as you breathe – nasal tissues that I didn't even know I had. I was ready to try anything, so on 3 January 2025, I went under the knife.

One month of healing later, I was the proud owner of a newly functional nose. I was able to breathe clear and deep out of both nostrils for the very first time. I learned that blowing your nose is an ecstatic pleasure, one I now enjoy as often as possible. And though my sleep apnoea wasn't cured, it did improve. The procedure probably led to a variety of other blessings, too. It turns out there are some surprising benefits to breathing out of your nose, and you don't necessarily need surgery to enjoy them. In fact, nose breathing might even improve your mental health.

The most obvious benefit to nasal breathing comes from those turbinates, according to Jacquelyn Callander, an ear, nose and throat doctor at the University of California, San Francisco. "They're kind of our primary mediator for warming and humidifying air, and that's incredibly important. But they also act as a filtration system," Callander says.

Together with your nose hairs, your hard working turbinates sift through dust, bacteria, viruses and more, an advantage you won't get from breathing through your mouth. "They can be the first line of defence for your immune system," she says.

It's not just the merits of nose breathing to consider, however. Breathing through your mouth has consequences. "There's a lot of research that associates mouth breathing with oral health problems," says Ann Kearney, a speech-language pathologist at Stanford University Medical Center who studies sleep and swallowing issues.

Mouth breathing has been shown to increase acidity and dryness in the mouth, linking it to cavities, demineralisation of the teeth and gum disease. A growing body of research also suggests mouth breathing as a child can affect the development of your teeth and jaw, leading to crooked teeth and even changing the shape of your face.

"It's simple. Your nose is for breathing and your mouth is for eating," Kearney says. For some people with seriously deviated septums or other nasal obstruction, nose breathing isn't an option. But she says a lot of mouth breathers can choose the nasal route in many circumstances. "It may not be comfortable at first. The shift from mouth to nasal breathing can be an adjustment," But, Kearney says, the perks kick in with each breath.

Most healthy people breathe through their noses when they sleep, but some open their mouths in a nocturnal quest for air. That's bad news, Kearney says. "It's about the position of the tongue."

Kearney says you can get a feel for this yourself. When your mouth is........

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