May 03, 2021 5 min read

The way you breathe can have a huge impact on your health. Deep breathing, for example, can reduce psychological and physiological stress and even lower your blood pressure. Similarly, how you breathe during sleep affects your sleep quality and — ultimately — your health.

Ideally, you should be breathing through your nose at all times. But if your nightly routine involves breathing through the mouth, you may have a problem. Things like obstructive sleep apnea, chronic nasal infections, enlarged tonsils, and a deviated septum can all cause mouth breathing once you doze off.

The issue with this is that it can compromise sleep quality and result in future health problems. That’s why treating mouth breathing is absolutely essential for well-being. Below, you’ll learn more about mouth breathing at night, including why it’s a problem, its causes, and potential solutions.


Why Worry About Mouth Breathing 

Occasionally breathing through the mouth is perfectly normal. Most people will do this when they have a cold, during vigorous exercise, and when feeling anxious. 

Mouth breathing only becomes a problem when it’s chronic, and some don’t even know they’re doing it because it happens when they’re not awake. Signs you may be a nocturnal mouth breather include: 

  • Feeling tired
  • Brain fog
  • Daytime sleepiness
  • Drooling 
  • Snoring
  • Dry mouth
  • Bad breath

In infants and children, this problem can affect the development of their facial skeleton, teeth placement, and concentration. In adults, mouth breathing can lead to and worsen sleep apnea by causing the upper airway to collapse. 

Nighttime mouth breathing can even dry out your mouth and cause bad breath, cavities, and gum disease. It’s also proven to cause mild dehydration and inadequate blood oxygen levels. In short, mouth breathing at night is bad for health.


What Causes Mouth Breathing at Night?

The main cause is an obstruction in the nose. Your nose is an important organ designed for breathing, while the mouth is primarily designed for eating. Only when the nose becomes obstructed does breathing switch to an alternative route — the mouth. 

In children, the most common causes of this obstruction are allergies, enlarged adenoids, enlarged tonsils, and a deviated septum. These are all things that can affect adults as well, along with nasal polyps, sinusitis, and anxiety. Some people, however, breathe this way out of habit. 

And if you have sleep apnea, that likely means you also breathe through your mouth during sleep. 


How Mouth Breathing Affects Sleep

In both children and adults, any kind of disordered breathing at night leads to poor quality sleep. We were designed to breathe through our noses, so breathing any other way is bound to cause problems in the long run. 

A study published inOtolaryngology-Head and Neck Surgeryand done on healthy subjects compared the effects of normal breathing to breathing when the nose was obstructed. It found that sleep was disrupted subjectively and objectively in the mouth breathing group. Specifically, these subjects woke up more often, had more changes in sleep stage, and spent more time in light sleep.

One reason why mouth breathing is so detrimental to sleep is that it makes breathing more difficult when you’re lying down. Very often,having the mouth open at night will cause the upper airway to collapse.This obstructs airflow and is the primary reason behind labored breathing, snoring, and most cases of sleep apnea.  

Mouth breathing at night can also make you lose more water and it can introduce harmful substances into your lower airway. Normally, your nose is a pretty effective filter and your body’s “air humidifier.” If obstructed, it can’t perform these important functions during sleep. 


How to Stop Mouth Breathing at Night

How you should treat your nightly mouth breathing largely depends on its causes. 

Most cases of this type of disordered night breathing are a result of colds and seasonal allergies. If that sounds like you, keeping your nose unblocked with the help of: 

  • Nasal irrigation
  • Decongestants
  • Antihistamines
  • Nasal sprays

Using a humidifier and/or air purifier in your home, and especially your bedroom, can also help reduce swelling and congestion inside your nose. 

However, if your case is a result of a skeletal deformity (e.g. a deviated septum), your doctor may recommend surgery. The same holds true in cases caused by sinus polyps, enlarged tonsils, enlarged adenoids, and abnormal sinus structure. Surgery is sometimes recommended for some cases of obstructive sleep apnea (OSA). In other cases, doctors will recommend non-invasive methods, like devices to help reduce sleep apnea symptoms:

  • CPAP devices
  • Continuous positive airway pressure (CPAP) devices work by delivering a stream of oxygenated air into your airways through a hose and mask. These are highly effective but uncomfortable to most.

  • Snoring mouthpieces
  • Milder cases of sleep apnea, as well as simple snoring, can both benefit from mouthpieces like mandibular advancement devices (MADs) and tongue-stabilizing devices (TSDs). These keep the jaw or tongue in place to keep the upper airway open.

    Further reading: Choosing the Best Anti-Snoring Device

    By reducing obstruction in the upper airway, these devices can make it easier for you to breathe through your nose. Make sure to speak to your doctor first before considering these devices. It could be that your breathing problems are due to something else.

    Catching a cold, having a stuffy nose, or being stressed are all things that can lead to occasional mouth breathing at night. But habitual mouth breathing is something completely different.

    This problem usually starts in childhood due to allergies or slight deformities in the airway. It can also happen in adulthood as obstructive sleep apnea and simple snoring. If left untreated, nocturnal mouth breathing can seriously affect development, health, and well-being. Addressing the problem as soon as you notice it can help you (and your loved ones) live a healthier life. 

    Depending on the causes, mouth breathing at night is easy to treat with simple decongestion, improving air quality, and snoring mouthpieces. See ourGood Morning Snore Solution Mouthpiece if interested in the latter. 


    1. Hopper SI, Murray SL, Ferrara LR, Singleton JK. Effectiveness of diaphragmatic breathing for reducing physiological and psychological stress in adults: a quantitative systematic review.JBI Database System Rev Implement Rep. 2019;17(9):1855-1876.doi:10.11124/JBISRIR-2017-003848
    2. Jefferson Y. Mouth breathing: adverse effects on facial growth, health, academics, and behavior.Gen Dent. 2010;58(1):18-80.
    3. Kim EJ, Choi JH, Kim KW, et al. The impacts of open-mouth breathing on upper airway space in obstructive sleep apnea: 3-D MDCT analysis.Eur Arch Otorhinolaryngol. 2011;268(4):533-539.doi:10.1007/s00405-010-1397-6
    4. Musseau D. Mouth Breathing and Some of Its Consequences. Int J Orthod Milwaukee. 2016;27(2):51-54.
    5. Abreu RR, Rocha RL, Lamounier JA, Guerra AF. Etiology, clinical manifestations and concurrent findings in mouth-breathing children.J Pediatr (Rio J). 2008;84(6):529-535.doi:10.2223/JPED.1844
    Olsen KD, Kern EB, Westbrook PR. Sleep and breathing disturbance secondary to nasal obstruction.Otolaryngol Head Neck Surg. 1981;89(5):804-810.doi:10.1177/019459988108900522

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