I never really thought much about how we breathe when we sleep until my son’s orthodontist brought it up. We were there for a routine appointment, and she started asking about his breathing habits. Did he sleep with his mouth open? Did he snore? Were his lips usually parted when he was resting?

She then explained why these things matter, not just when it comes to teeth and jaw development, but for our overall health, too. Then, that conversation got me curious, so naturally, I started looking into it more. And the more I read, the more I realized there was quite a bit to learn about something most of us do without giving it a second thought.

So today, let’s talk about mouth breathing. What actually happens when we breathe through our mouths instead of our noses? Why does nasal breathing matter, especially when we’re sleeping? What about mouth taping?

It might sound a little strange at first, but it’s been getting more attention, including in conversations around dental and sleep health. Let’s look at what we know, what the research says, and what’s worth keeping in mind.

What Mouth Breathing is Doing To Your Body

Here’s something I didn’t really think about before: your nose and mouth don’t do exactly the same job when it comes to breathing. Your nose is designed to do more than just let air in. It actually prepares that air before it reaches your lungs. Your mouth can also be used for breathing, of course, but it doesn’t provide all the same benefits.

When you breathe through your nose, quite a bit happens before that air ever reaches your lungs. The tiny hairs and mucus inside your nose help trap dust, pollen, and other particles. Your nasal passages also warm and humidify the air, making it more comfortable for your airways. When you breathe through your mouth, you bypass much of that process, so the air isn’t warmed and humidified in quite the same way. It might not sound like a big deal, but these little functions are part of how your respiratory system protects and supports your body.

The Nitric Oxide Piece

This is another interesting part of nasal breathing that I hadn’t really thought about before.

Your nose and sinuses produce a gas called nitric oxide. When you breathe through your nose, some of that nitric oxide travels with the air into your lungs. It helps regulate blood vessel function and plays a role in how blood flows through the lungs, which supports the exchange of oxygen and carbon dioxide.

Nitric oxide also has antimicrobial properties, although its role in protecting us from infections is more complex than simply breathing through your nose to keep bacteria out.

So, does breathing through your mouth mean your body can’t get enough oxygen? Not necessarily. Your body can still take in oxygen through your mouth, and we naturally switch to mouth breathing during activities like exercise when we need more air. The bigger concern is when mouth breathing becomes a regular habit, particularly during sleep. Mouth breathing can leave you waking up with a dry mouth or throat, and sometimes it happens because your nose is blocked or you’re not breathing well through your nose. It can also go hand in hand with snoring. When you think about how many hours we spend sleeping every night, it makes you wonder how often this is happening without us even realizing it.

Studies have found that nasal breathing can increase oxygen uptake in the blood by approximately 10% compared to mouth breathing. Better oxygen delivery means better energy, better cognitive function, better recovery. (Santa Teresa Smiles / Dental Airway Research, 2024)

What Chronic Mouth Breathing Actually Does to You

Mouth breathing can affect more than just your mouth. Depending on why it’s happening, it can also be linked to changes in jaw development, jaw tension, and the way you hold your head and neck.

Jaw and Neck

This is the part I found particularly interesting. When you breathe through your nose with your mouth closed, your tongue will usually rest against the roof of your mouth, and your jaw can stay in a more relaxed position.

With mouth breathing, the tongue often rests lower in the mouth, and the jaw stays open more frequently. If this becomes a regular pattern, it can affect how the muscles around your mouth and jaw work. In children, chronic mouth breathing can also be associated with changes in facial and jaw development, which is one reason orthodontists pay attention to it. You might also notice yourself holding your head further forward, particularly if you’re trying to make breathing through your nose easier. That position can put extra strain on your neck and shoulders, and some people experience jaw tightness or tension headaches along with it.

Teeth grinding and clenching can also occur alongside mouth breathing, especially in people who have sleep-disordered breathing. But it’s not as simple as mouth breathing directly causing grinding. There can be several things going on, including airway obstruction and disrupted sleep.

“When we breathe shallowly from the chest or mouth, the neck and jaw muscles overwork to help stabilize the head and upper airway. Over time, this constant recruitment can cause tightness in the jaw, face, and suboccipital muscles, contributing to clenching, headaches, and overall facial tension.” — Dr. Pamela Marzban, DDS & Dr. Sara Black, Zia Physio

Your teeth and your oral health

Saliva does a lot more for your mouth than you might realize. It helps wash away food particles, neutralize acids, and protect your teeth from the bacteria that can lead to cavities. When you breathe through your mouth while you sleep, your mouth can become really dry, especially if this happens night after night. With less moisture in your mouth, your teeth lose some of that natural protection. You may wake up with a dry tongue, bad breath, or that sticky feeling in your mouth. Over time, a dry mouth can also increase your risk of cavities and gum problems.

Dentists can sometimes spot signs of dry mouth during a checkup, especially if you’re dealing with more cavities than usual or irritated gums. If you wake up with a dry mouth most mornings, it’s worth mentioning to your dentist and looking at whether mouth breathing could be part of the reason.

Jaw development – especially in kids

This is the part that really caught my attention, especially after our orthodontist brought it up when we took my son in for his appointment.

A child’s face and jaw are still developing as they grow, and the way they breathe can be part of that picture. When the mouth is closed, the tongue generally rests against the roof of the mouth. With ongoing mouth breathing, the tongue tends to sit lower instead. Over time, this may be associated with differences in how the palate, jaw, and dental arch develop. You might have heard the term “adenoid face.” It’s an older term sometimes used to describe certain facial features seen in children who breathe through their mouths, such as a longer face or a narrower upper jaw. But these features don’t happen to every child who mouth breathes, and facial shape alone doesn’t tell you how a child is breathing.

What matters is figuring out why a child is breathing through their mouth. Enlarged adenoids or tonsils, allergies, and ongoing nasal congestion can all make nasal breathing difficult. If a child regularly sleeps with their mouth open or snores, it’s worth bringing up with their dentist or doctor.

What I learnt from that appointment was how something as simple as the way a child breathes can be worth paying attention to. If your child regularly sleeps with their mouth open or snores, it’s worth asking their dentist or doctor about it rather than assuming it’s just a habit they’ll grow out of.

Your sleep quality

Mouth breathing during sleep can be linked to snoring, disrupted sleep, and sleep apnea. My own sleep still isn’t the best for a few different reasons, but I’ve noticed a real improvement since I started mouth taping.

When you breathe through your mouth at night, your mouth and throat can dry out, and you may be more likely to snore. In some people, mouth breathing also goes along with a narrower or partly blocked airway, which can interrupt sleep throughout the night. That’s why you can sleep for seven or eight hours and still wake up feeling exhausted. You might not even realize your sleep is being interrupted. Nasal breathing is also associated with slower, more controlled breathing, which can help support a calmer state. But if you’re regularly waking up tired, snoring heavily, or gasping in your sleep, it’s worth checking for an underlying breathing problem rather than assuming mouth breathing is the only cause.

Immune system

Your nose does quite a bit to protect you from things in the air. The tiny hairs, mucus, and cilia inside your nasal passages help trap particles and move them out before they reach your lungs. Your nose also produces nitric oxide, which plays a role in how your airways function. When you breathe through your mouth, you miss some of that filtering and conditioning, and if you’re doing it throughout the night, it can also leave your mouth and throat feeling dry.

Poor sleep can affect your immune system, too. So while mouth breathing doesn’t automatically mean you’ll get sick more often, it’s another reason to pay attention to your breathing, especially if you’re also snoring or not sleeping well.

So, Does Mouth Taping Actually Work?

Mouth taping is pretty much what it sounds like. You put a small piece of tape over your lips before bed to help keep your mouth closed while you sleep. I know it sounds strange. Honestly, that was my first thought, too. But once I started looking into why people do it, I could understand the idea behind it a little better.

What the research actually says

Mouth taping has become pretty popular on social media, and there are a lot of claims out there about what it can do. But the research is still limited, so I wouldn’t take everything you see online as fact.

There have been a few reviews looking at the research so far. One published in PLOS One in 2025 looked at 10 studies and found some potential benefits for certain people, including improvements in a few measures related to sleep apnea. Another review, published in the American Journal of Otolaryngology in 2025, also looked at the possible benefits, including snoring and mouth leaks in people using CPAP machines. So there’s some interesting research, but we still need better studies to understand who might benefit and whether it’s safe.

On a personal note, I’ve noticed that mouth taping has helped my son with his snoring. That got my attention, but I also know that what works for one person isn’t necessarily right for everyone.

Some studies have found improvements in snoring, and one reported less daytime fatigue in people with mild sleep apnea. The research is still limited, so we need more studies before we can say who mouth taping might help. Personally, I’ve noticed a difference, too, and I can understand why people are interested in whether breathing through their nose at night might help them sleep more comfortably.

What about safety?

This is probably one of the first questions that comes to mind, and it’s a fair one. Mouth taping isn’t right for everyone, even if you’ve seen lots of people online talking about how much they love it. If you have trouble breathing through your nose because of congestion or a blockage, taping your mouth isn’t a good idea. The same goes for people with certain sleep-related breathing problems, and for children, it’s best to speak with a healthcare provider before trying it.

If you’re curious about mouth taping, it’s worth figuring out whether you can breathe comfortably through your nose first. If you snore regularly or suspect you might have sleep apnea, get that checked rather than using tape to try to manage it yourself. I know the idea sounds simple, but being able to breathe comfortably matters more than keeping your mouth closed overnight.

How to Actually Start

The tape

If you’re looking into mouth tape, you’ll find a few different options online and at pharmacies. Some are made specifically for sleeping, while others use gentle surgical tape. Whatever you come across, be careful with anything that could make it difficult to open your mouth or breathe comfortably. And if you have sensitive skin or any trouble breathing through your nose, check with a healthcare professional before trying it.

Start by testing your nasal breathing

Before trying mouth taping at night, get used to breathing through your nose during the day first. Keep your lips gently closed, let your tongue rest against the roof of your mouth, and breathe normally through your nose. If you find that difficult because your nose is often blocked, look into what’s causing it. A saline rinse before bed, a humidifier, or a nasal strip may help, depending on the reason.

Give it at least two weeks

The first few nights might feel a little strange and uncomfortable, especially if you’re not used to sleeping with your mouth closed. I noticed less dryness when I started, and it seemed to help with my jaw and neck tension, too. Everyone’s different, though, and there’s no guarantee you’ll notice the same changes.

Tongue posture matters too

Tongue position matters, too. When your mouth is resting, your tongue should sit gently against the roof of your mouth, with your lips closed and your teeth relaxed rather than clenched. You might have heard people online call this “mewing.” It’s become quite a trend, but resting your tongue this way is actually normal. Just let it sit there naturally rather than pushing it up or forcing it into position. There’s a lot of talk online about changing your jaw shape this way, but the evidence doesn’t really support those claims.

For Kids, See A Professional First

If you’re thinking about mouth taping for your child, talk to their dentist or doctor first. Kids often breathe through their mouths because something is making it hard to breathe through their noses, like enlarged tonsils or adenoids. It’s worth finding out what’s going on before trying to keep their mouths closed at night. Depending on the cause, they might need treatment for the airway or help from an orthodontist or a myofunctional therapist.

We breathe all day and all night without really thinking about it. But if you’re regularly breathing through your mouth while you sleep, you might wake up with a dry mouth, and it can sometimes go along with snoring or restless sleep. Nasal breathing has its own benefits, too, including helping warm and filter the air we breathe.

Simply Salt & Soul

The Salt (The Science): Breathing affects more than we might think. It plays a role in our sleep, oral health, and how our bodies take in oxygen. We don’t always think about how we’re breathing, especially when we’re asleep, but it can make a difference to our overall health.

The Soul (The Wellness): We breathe all day without giving it much thought. Sometimes, just slowing down and taking a moment to notice your breath can help you feel a little more settled. It’s a small thing, but it’s part of taking care of yourself, too.

Have you ever tried mouth taping? Leave a comment and let me know!

Sources & References:

• Rhee J. et al., PLOS One (May 2025)  Fangmeyer SK et al., American Journal of Otolaryngology (2025)
• PMC: Impact of Mouth Breathing on Dentofacial Development (2022)
• Cleveland Clinic: Nose vs Mouth Breathing
• Santa Teresa Smiles / Nasal Nitric Oxide Research (2024)
• Dr. Pamela Marzban, DDS & Dr. Sara Black, Zia Physio (2026)
• Presidential Holistic Dentistry: Mouth Breathing and Facial Growth (2025)
• Uniphysio & Associates: Mouth Breathing Jaw Pain
• INTEGRIS Health: Mouth vs Nasal Breathing (2026)