Last updated: October 2026
Mouth breathing at night usually happens because your nose is blocked (a cold, allergies, polyps, a narrow nasal passage or big adenoids) or because your mouth falls open when you sleep on your back. It can cause a dry mouth, snoring, poorer sleep and a higher risk of tooth decay. Clear your nose first, then fix your position.
Below: a quick self-check, causes, effects, 10 ways to stop it, an honest look at mouth taping, and when to see a GP.
Snoring loudly, gasping or always tired? Mouth breathing on its own is usually harmless. But if someone has seen you stop breathing, gasp or choke in your sleep, or you’re very sleepy in the day, see a GP. These can be signs of sleep apnoea, which needs proper treatment and is a firm reason not to tape your mouth shut.
Quick self-check: do you mouth breathe at night?
You can’t watch yourself sleep, so look for the clues:
- You wake with a dry mouth, dry tongue or cracked lips, or drink water in the night.
- There’s drool on your pillow.
- Your partner says you sleep with your mouth open, or you snore.
- Your morning breath is worse than you’d expect.
- Your nose often feels blocked at bedtime, or one side never seems clear.
- You wake unrefreshed, even after a full night. See why do I wake up tired?
Two or three ticks suggest you mouth breathe for at least part of the night. The fix depends on the cause, so that’s the next step.
Causes of mouth breathing at night
You switch to mouth breathing when your nose can’t move enough air, or when your jaw relaxes and your mouth drops open.
| Cause | Clues | What helps |
|---|---|---|
| A cold or sinusitis | Blocked nose; with sinusitis, pain around the cheeks, eyes or forehead (usually clears within 4 weeks) | Salt water nose rinses, fluids, rest. See how to sleep with a cold |
| Allergies (dust mites, pets, pollen, mould) | Sneezing, itchy nose, watery eyes; worse in bed or in certain seasons | Hot-wash bedding, pets out of the bedroom, pharmacy antihistamines or steroid spray |
| Nasal polyps | A nose blocked for weeks, reduced smell, snoring | See a GP: usually steroid drops or spray |
| A narrow or bent nasal passage | One side always feels more blocked than the other | A GP can look inside your nose and refer you if needed |
| Big tonsils or adenoids (mainly children) | Snoring, mouth open at rest, glue ear or ear infections | See a GP; adenoids usually shrink as children grow |
| Sleeping on your back | Snoring and an open mouth are worse on your back | Side sleeping. See the best sleeping position |
| Alcohol or sleeping pills | Worse after a drink or a sleeping tablet | Cut back, especially close to bedtime. See alcohol and sleep |
| Obstructive sleep apnoea | Loud snoring, gasping or choking, breathing pauses, daytime sleepiness | See a GP for a sleep study |
| Habit | Nose feels clear, but your mouth still falls open | Side sleeping, a chin strap, daytime nose breathing practice |
The NHS adds that being overweight and smoking make snoring more likely. See how to stop snoring and sleep and weight loss.
Is mouth breathing at night bad for you?
Now and then, with a cold, it isn’t a problem. Night after night, it has knock-on effects worth fixing.
Dry mouth and bad breath
The NHS lists breathing through your mouth at night as one of the main causes of a dry mouth, and dry mouth as one cause of bad breath. Many people also wake with a scratchy throat.
Teeth and gums
Saliva protects your teeth, and the NHS says a dry mouth makes tooth decay more likely. In a small 2016 study of 10 healthy adults, the mouth became more acidic during sleep when they had to breathe through it (average pH 6.6, against 7.0 normally), which the authors note has been proposed as a factor in dental erosion and decay.
Snoring and poorer sleep
The NHS names a mouth falling open in sleep as one cause of snoring. A 2026 meta-analysis found that blocking the nose was linked to around 14 more breathing events an hour on the apnoea-hypopnoea index (AHI), and could cause sleep apnoea-like patterns in previously healthy people. If snoring is keeping a partner awake, see sleep divorce.
Does mouth breathing at night make you tired?
It can, through snoring, a dry mouth waking you and, in some people, sleep apnoea. Being tired despite enough hours in bed is the bigger signal to act on. See waking up with a headache and why am I always tired?
How to stop mouth breathing at night: 10 steps
Open the nose up first: keeping your mouth shut while your nose is blocked doesn’t work and isn’t safe.
- Rinse your nose before bed. The NHS recipe: 1 teaspoon of salt and 1 of bicarbonate of soda in a pint of boiled water that has cooled, sniffed into one nostril at a time over a sink. Pharmacy saline sprays are easier.
- Use decongestant sprays briefly. The NHS says no longer than 5 days, as they can make a blocked nose worse. Not for children under 6.
- Treat allergies. If your nose is worse in bed, think dust mites or pets. The NHS suggests washing bedding at 60C or above, damp dusting, a HEPA vacuum and keeping pets out of the bedroom. A pharmacist can suggest antihistamines or a steroid nasal spray.
- Sleep on your side. The NHS suggests a tennis ball stitched to the back of your sleepwear, or a special pillow or wedge. See the best sleeping position.
- Try nasal strips or dilators. The NHS lists them for narrow nasal airways. Be realistic: in a small 2001 trial in 18 heavy snorers, strips widened the nose and made it feel clearer, but didn’t change snoring time or loudness overall.
- Consider a chin strap. For a mouth that falls open, the NHS mentions a chin strap or a mouth device that encourages nose breathing (a vestibular shield). Only if your nose is clear.
- Go easy on alcohol, and avoid sleeping pills. The NHS says both can cause snoring. See alcohol and sleep.
- Stop smoking and keep to a healthy weight. Both are on the NHS list for snoring and sleep apnoea.
- Get the bedroom air right. Very dry winter air can make a dry mouth feel worse, and some people find a clean humidifier helps. Don’t overdo it: the NHS advises keeping your home dry and well ventilated if you have allergies, as damp feeds mould. See the best temperature for sleep.
- Protect your mouth meanwhile. Keep water by the bed, brush twice a day, use an alcohol-free mouthwash and chew sugar-free gum, as the NHS suggests for dry mouth.
If it’s habit: practising slow nose breathing in the day, such as box breathing or 4-7-8 breathing, can make it feel more natural. There’s little research on whether this changes how you breathe asleep, so treat it as a gentle extra.
A calmer wind-down
No supplement stops mouth breathing. What you can control is the hour before bed: a steady bedtime routine, a nose rinse, and a warm, alcohol-free drink instead of a nightcap. See 12 sleep hygiene habits.
Our Magnesium Glycinate Sleep Complex is a caffeine-free berry drink with magnesium bisglycinate and citrate (148mg magnesium per serving), glycine, L-theanine, chamomile, passionflower, hops and oat straw. Magnesium contributes to the normal functioning of the nervous system and to the reduction of tiredness and fatigue. Adults only. More in magnesium for sleep.
Mouth taping: an honest look
Taping your lips shut at night is all over social media. The research is far thinner than the hype.
- A 2025 systematic review found just 10 studies, with 213 patients in total. Two showed improvements in sleep apnoea measures; the others found no difference. The authors warned of a potentially serious risk of harm, including suffocation if the nose is blocked; many studies excluded anyone with nasal problems.
- A 2025 scoping review of nine studies found little agreement on any benefit, and that few of the claims made on TikTok had ever been tested.
- A 2026 meta-analysis could find only two mouth taping studies, both in mild sleep apnoea, so there wasn’t enough data to pool them.
In short: it may help a few mild, mouth-breathing snorers, but there’s no good evidence it improves sleep for healthy people, and it isn’t a treatment for sleep apnoea.
Never tape your mouth if:
- your nose is blocked, even partly, or you have a cold, hay fever or sinusitis
- you’ve been drinking alcohol or taken sleeping pills or other sedating medicines
- you have, or might have, sleep apnoea (loud snoring, gasping, breathing pauses): tape can quieten the snoring that tells you something is wrong
- you feel sick, or could vomit in the night
- it’s for a child
We cover the studies, the claims and safer ways to try it in our full guide to mouth taping.
Mouth breathing in children
In children, enlarged adenoids or tonsils are a common reason. The NHS says big adenoids can cause mouth breathing, snoring, sleep apnoea, glue ear or repeated ear infections. Adenoids usually start to shrink around the age of 4 and have gone by early adulthood, so a doctor may suggest waiting rather than surgery.
- See a GP if your child snores most nights, always breathes through their mouth, pauses or gasps in their sleep, or is tired and irritable in the day.
- Never tape a child’s mouth.
- No decongestants under 6, and the NHS says homemade salt water washes aren’t suitable for children; ask a pharmacist instead.
- Evopure products are for adults (18+) only.
Mouth breathing in pregnancy
A stuffy nose is common in pregnancy: a 2026 review explains that rising oestrogen and progesterone make the nasal lining swell, which can lead to mouth breathing and snoring. Side sleeping, nasal strips and saline rinses can help the nose feel clearer, though they haven’t been shown to treat sleep apnoea in pregnancy, and mouth taping has no pregnancy safety data. Check with a pharmacist or midwife before any medicated nasal spray, and mention loud snoring or daytime sleepiness to your midwife or GP. We don’t recommend our products during pregnancy or breastfeeding.
When to see a GP
See a GP if:
- your breathing stops and starts in your sleep, or you gasp, snort or choke
- you snore loudly and wake unrefreshed or with headaches, or feel sleepy in the day
- your nose has been blocked for weeks, one side is always blocked, or your sense of smell has changed
- your dry mouth hasn’t improved after a few weeks of self-help, or your mouth is sore, red or bleeding
NICE guidance tells GPs to assess for obstructive sleep apnoea if you have two or more features such as snoring, witnessed breathing pauses, unrefreshing sleep, waking headaches, unexplained sleepiness, waking to pee or choking in your sleep. Bring a partner who has heard you at night if you can. Your GP may refer you for a sleep study, usually done at home. See sleep apnoea: symptoms, tests and treatment.
If you drive: you must tell the DVLA if you have confirmed moderate or severe obstructive sleep apnoea with excessive sleepiness, and not drive until your symptoms are under control. Not telling the DVLA about a condition that affects your driving can mean a fine of up to £1,000.
See a dentist if you notice sensitivity, decay or bleeding gums. If you also clench at night, see teeth grinding.
If your blocked nose is worst in bed and first thing in the morning, read why dust mite allergy is worse at night.
FAQs
Is it bad to sleep with your mouth open?
Occasionally, for example with a cold, it’s fine. Night after night it can cause a dry mouth, snoring, bad breath and a higher risk of tooth decay, and it can be a sign of a blocked nose or sleep apnoea.
Why do I breathe through my mouth at night when my nose isn’t blocked?
Your jaw may relax and fall open, especially on your back or after alcohol. Dust mite or pet allergies can also make your nose worse in bed, even if it feels fine in the day.
How do I stop mouth breathing at night without tape?
Rinse your nose with salt water before bed, treat allergies, sleep on your side, try nasal strips or a chin strap, and cut back on alcohol near bedtime. See a GP if your nose is always blocked.
Does mouth breathing at night make you tired?
It can, usually through snoring, a dry mouth waking you, or sleep apnoea. If you’re very sleepy in the day or someone has seen you stop breathing in your sleep, see a GP.
Is mouth taping safe?
Not for everyone. A 2025 systematic review found little evidence of benefit and a potential risk of harm. Never tape if your nose is blocked, after alcohol or sedatives, if you might have sleep apnoea, or on a child.
Can mouth breathing at night damage your teeth?
It can raise the risk. Saliva protects teeth, and the NHS says a dry mouth makes tooth decay more likely. Brush twice a day and tell your dentist.
Why do I wake up with a dry mouth?
Common causes are mouth breathing at night, a blocked nose, not drinking enough, some medicines and anxiety. See a GP if it doesn’t settle with self-help.
Sources
- NHS. Snoring.
- NHS. Sleep apnoea.
- NHS. Dry mouth and Bad breath.
- NHS. Allergic rhinitis, Sinusitis and Nasal polyps.
- NHS. Adenoidectomy.
- NICE (2021). Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202).
- GOV.UK. Excessive sleepiness and driving.
- Rhee J et al (2025). Breaking social media fads and uncovering the safety and efficacy of mouth taping in patients with mouth breathing, sleep disordered breathing, or obstructive sleep apnea: a systematic review. PLoS One. PMID 40397877.
- Fangmeyer SK et al (2025). Nocturnal mouth-taping and social media: a scoping review of the evidence. American Journal of Otolaryngology. PMID 39662104.
- Alshehri NA et al (2026). Impact of nasal obstruction and mouth taping on sleep apnea indicators: systematic review and meta-analysis. OTO Open. PMID 42662994.
- Choi JE et al (2016). Intraoral pH and temperature during sleep with and without mouth breathing. Journal of Oral Rehabilitation. PMID 26666708.
- Djupesland PG et al (2001). Dichotomous physiological effects of nocturnal external nasal dilation in heavy snorers. American Journal of Rhinology. PMID 11345160.
- Babbar S, Maulik D (2026). Nasal breathing in pregnancy: a narrative review of physiology, dysregulation and therapeutic interventions. Journal of Maternal-Fetal and Neonatal Medicine. PMID 42705916.
This guide is general information, not medical advice. If you think you have sleep apnoea, see a GP. Evopure makes the Magnesium Glycinate Sleep Complex, which is for adults only. We don’t recommend our products during pregnancy or breastfeeding.
