How to Stop Mouth Breathing at Night (and Reduce Snoring)

You cannot control how you breathe while you are asleep. What you can do is change your daytime breathing so that the nose becomes your body's default, which is the only real lever you have over what happens at night. This is a step by step approach: how to check whether your nose is actually usable, how to build your body's confidence in nasal breathing, and where tools like tape and nasal dilators fit, which is later than most people think.

Start with a doctor if any of this sounds familiar

Before anything else, snoring can be a symptom of obstructive sleep apnoea, a condition where your airway collapses repeatedly during the night and your breathing actually stops for stretches of ten seconds or more. It is common, it is frequently undiagnosed, and it carries real cardiovascular risk. No amount of breath retraining substitutes for a diagnosis.

Go and see a doctor if any of these apply:

• Your partner has noticed you stop breathing, gasp or choke in your sleep.
• You wake up unrefreshed no matter how long you sleep.
• You are sleepy during the day, particularly if you have ever nodded off driving.
• You wake with headaches or with a very dry mouth every morning.
• Your snoring is loud and happens most nights.

Everything below is still useful alongside proper treatment. It is not a replacement for it.

What is actually happening when you snore

Snoring is a vibration, and understanding where it comes from tells you a lot about what will and will not help.

When you fall asleep, the nerve signals that keep your muscles toned get dialled down. That is normal, and it is why people do not snore sitting upright and awake in the same position they snore in at night. But it means the soft tissues at the back of your throat, the soft palate, the uvula, the base of your tongue and the walls of the pharynx, go slack. None of them are supported by bone or cartilage. They sag.

Now push air past slack tissue in a narrowed tube and you get turbulence, and turbulence makes those tissues flutter. That flutter is the sound. The soft palate and the uvula, the small dangly bit at the back of your throat, are the usual culprits.

So snoring needs two ingredients: a narrowed airway and airflow moving fast enough to be turbulent. Anything that narrows the airway makes it worse: lying on your back, because gravity pulls the tongue and palate backwards; alcohol, which relaxes those muscles further; a blocked nose, which forces you to work harder to pull air through; extra tissue around the neck and throat; and mouth breathing itself, which we will come to.

The frustration is legitimate. It happens entirely in your unconscious state, so there is no moment where you can catch it and correct it. But things you change during the day shift what your body defaults to at night, and that is where the leverage sits.

What mouth breathing at night does

James Nestor, the journalist who wrote Breath, ran an experiment on himself at Stanford with rhinologist Dr Jayakar Nayak. He and one other participant had their nostrils plugged with silicone and taped shut for ten days, forcing them to breathe entirely through the mouth, then spent ten days on nasal breathing only.

The mouth breathing phase was rough. Blood pressure climbed by around 13 points, pushing him into stage one hypertension. Heart rate variability, a measure of how well the nervous system is coping, dropped. He became foggy and exhausted, developed insomnia, and started snoring heavily and having obstructive sleep apnoea events, having had neither before. The nasal breathing phase reversed it.

Two people, self-funded, not a controlled trial, and Nestor says as much himself. It is an anecdote, but a vivid and carefully instrumented one, and it lines up with broader research showing that mouth breathing at night is associated with more snoring and more disrupted breathing.

Opening your mouth lets the jaw drop back and down, which narrows the airway at the throat, exactly where the vibration happens. It also bypasses the nose, where air gets warmed, filtered, humidified and slowed down. Mouth air arrives cold, dry and fast, which dries the tissues out and makes turbulence more likely.

Why mouth tape is not step one

Mouth taping has taken off, and plenty of people report it made a real difference to their snoring. That is worth taking seriously.

But taping your mouth shut when your nose does not work is not a good idea. If your body is not confident it can get enough air through your nose, closing off the backup exit does not create calm nasal breathing. It creates panic. There is also a genuine safety issue here: studies looking at mouth taping have flagged the risk of restricting airflow in people with an obstructed nose.

Get the nose working first, then consider whether you need the tape at all. A lot of people find they do not.

Step 1: find out whether your nose actually works

Can you breathe through your nose clearly and easily? Your mouth is meant to be the emergency valve, not the main road.

The basic test. Sit comfortably and breathe in through your nose and out through your nose, gently. Now see if you can slow it down. You are aiming to comfortably breathe in for around five seconds and out for around five seconds, with no strain and no sense of needing to gulp.

The nostril test. Do it again, but this time close off your right nostril and breathe in through the left for five and out through the left for five. Then swap: right nostril in for five, out through the right for five. Notice whether one side is noticeably harder work than the other.

If there is a difference, do not panic. Your nostrils alternate which one is more open throughout the day. This is called the nasal cycle and it is entirely normal, switching every few hours. There is a much older idea, from yogic tradition, that the alternation relates to different sides of the brain being more active, and that alternate nostril breathing brings the two into balance. Some early research looked at this. It is not well established, and I would treat it as an interesting old idea rather than a settled fact.

What you are looking for is not a mild difference between sides. It is a serious, persistent blockage. If one side is just a bit congested, test again in a few hours and see whether it has switched over.

If both sides are properly blocked most of the time, that is a structural or medical question, not a technique question. Chronic rhinitis, allergies, enlarged adenoids and a deviated septum are all common and all treatable. Get it looked at, because no amount of practice will out-train a physically blocked airway.

Step 2: make space in the body

Your ability to breathe well through the nose is not just about the nose. If your ribcage and diaphragm have no room to move, everything upstream gets harder.

A few things that help:

• Gentle stretches and light inversions to open through the ribs and the front of the body.
• Tucking the tailbone under slightly, which stacks the ribcage over the pelvis and gives the diaphragm room to descend properly.
• Generally undoing the collapsed-forward shape most of us spend the day in.

If this is new to you, diaphragmatic breathing covers the posture side in more detail, including why position comes before technique.

Step 3: build your CO2 tolerance

Your urge to breathe is triggered by carbon dioxide, not by a lack of oxygen. If your body's CO2 alarm is set too sensitively, it will trip early, and you will feel air hunger long before you actually need air. Your body's fix for that is to breathe faster and shallower, and to reach for the quickest possible route, which is the mouth.

That is why so many people cannot sustain nasal breathing. It is not that their nose is blocked. It is that nasal breathing naturally slows things down, CO2 rises slightly, the alarm goes off, and they bail out to the mouth.

Raise your CO2 tolerance and the alarm settles. Nasal breathing stops feeling like restriction and starts feeling normal, and your body is far more likely to hold that pattern when you are not consciously running it. CO2 tolerance training walks through how to build this.

Step 4: take nasal breathing for a walk

The fastest way to teach your body that the nose is safe is to use it under mild demand.

Start with walking. Keep your mouth closed and breathe entirely through your nose. Then walk uphill. Then try a very light jog. You are looking for the level of effort where nasal breathing is challenging but sustainable, not the level where you are gasping.

Over a few weeks this does two things: it raises your CO2 tolerance without any formal practice, and it builds genuine confidence in the nose as a functioning airway. Research on nasal breathing during exercise has generally found it does not improve performance outcomes like VO2 max, but it can improve breathing efficiency, and for this purpose efficiency is exactly the point.

Step 5: humming

Breathe in through your nose, then hum on a long exhale.

That vibration does something specific. Your paranasal sinuses, the air-filled cavities around your nose and eyes, produce nitric oxide, a gas your body uses for signalling. It widens blood vessels and plays a part in defending against bacteria and viruses in the airway. The problem is that the sinuses connect to the nasal passage through small openings, so most of that gas just sits there.

Humming makes the air oscillate and flushes it out. A 2002 study by Weitzberg and Lundberg measured a fifteen-fold increase in nasal nitric oxide during humming compared with a quiet exhale. It was a small study of ten healthy people, but the effect is large and it has been reproduced since.

Follow-up work found that the peak drops off with repeated consecutive hums and recovers after a few minutes of quiet, so a burst of humming with pauses beats humming continuously. Low-pitched humming also appears to produce more than high-pitched humming. Try it as part of a wind-down, a few minutes before bed.

Step 6: strengthen the airway itself

This one has the strongest research behind it of anything on the page.

If snoring comes from slack tissue at the back of the throat, training the muscles of the tongue, soft palate and throat should reduce it, and the studies bear that out. The work is called myofunctional therapy, or oropharyngeal exercises, and it comes originally out of speech therapy.

• A 2018 systematic review and meta-analysis by Camacho and colleagues found that these exercises reduced snoring in adults, on both self-reported questionnaires and objective sleep studies.
• A 2015 randomised trial published in Chest found oropharyngeal exercises reduced snoring specifically.
• A 2009 trial by Guimarães and colleagues found the same exercises improved moderate obstructive sleep apnoea.
• A randomised controlled trial found that four months of learning the didgeridoo significantly reduced sleep apnoea severity, because playing it trains exactly those upper airway muscles.

The exercises themselves are unglamorous: tongue presses against the roof of the mouth, sliding the tongue along the palate, holding the soft palate up, cheek and swallowing work. A speech pathologist or myofunctional therapist can give you a proper programme. If you want the fun version, learn an instrument that requires sustained breath control.

Where the tools fit

Once the nose is working and the daytime pattern is retrained, these become genuinely useful rather than a crutch over an unfixed problem.

Humidifier. Straightforward and worth it. Dry air irritates and congests nasal passages overnight, particularly with heating or air conditioning running. Humidified air is easier to move through the nose.

Nasal dilators. These physically hold the nostrils open, either internally or as an external strip across the bridge of the nose. They can help when the limitation is at the nasal valve, the narrowest point just inside the nostril. They will do nothing for snoring that originates at the throat. The evidence is mixed, so treat them as worth trying rather than proven.

Side sleeping. Free, and often surprisingly effective, because it takes gravity out of the equation. Positional trainers exist if you keep rolling onto your back.

Mouth tape. This is the point to consider it, not before. Test a small piece of skin-safe tape while awake first. Never use it if you cannot breathe comfortably through your nose, and never as a substitute for getting apnoea assessed.

Mandibular advancement devices. These are the mouthpieces you may have seen, and they are widely misunderstood. They do not work by nudging you towards nose breathing. They work by holding your lower jaw slightly forward, which physically pulls the tongue and soft tissue away from the back of the airway. They need fitting properly, and are worth discussing with a dentist who does sleep work.

The short version

1. Rule out sleep apnoea. Everything else is secondary to this.
2. Test your nose. Five seconds in, five seconds out, each nostril separately.
3. If you are properly blocked most of the time, get it medically assessed.
4. Make space in the body. Posture, tailbone tucked, ribs free.
5. Build CO2 tolerance so nasal breathing stops feeling like restriction.
6. Take nasal breathing into walking and light jogging.
7. Hum before bed.
8. Train the airway muscles themselves.
9. Then, and only then, add the tools: humidifier, dilator, side sleeping and tape.

The order is the whole point. Most people start at step nine, find it uncomfortable or ineffective, and conclude it does not work for them.

Related reading

If you want a gentler evening routine once nasal breathing is comfortable, see our guide to breathing for better sleep. It covers the full day rather than asking one bedtime trick to solve everything.

This article is for general information and is not medical advice. Snoring can be a symptom of obstructive sleep apnoea. If you snore loudly, wake unrefreshed, or your partner has noticed you stop breathing in your sleep, please see a doctor.