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Mouth Breathing: Symptoms, Causes & Treatment

Alyssa Hill Headshot
Written by
Alyssa Hill
Medically Reviewed by 
Dr. Lara Coseo
4 Sources Cited

What is Mouth Breathing?

Mouth breathing is when you inhale and exhale through your mouth rather than your nose.

Breathing through the nose is the proper way to breathe because it warms up the nasal passages and moistens the air you take in.

Mouth breathing dries out the mouth, which can eventually cause cavities and gum disease. Most people do not realize they mouth breathe because it usually happens while sleeping.

Some people exclusively breathe through their mouth, even during the day. This condition can also disrupt your sleep, which may cause fatigue throughout the day.

Advantages of Nose Breathing vs. Mouth Breathing

Nasal breathing, rather than mouth breathing, is better for your oral and general health. This is because your nose produces nitric oxide, which improves the lungs’ ability to absorb oxygen.

Nitric oxide also provides antiviral, antifungal, antibacterial, and antiparasitic properties. Thus, boosting your immune system and making it easier for you to fight off infections.

Causes of Mouth Breathing

The primary cause of mouth breathing is due to a partially or fully blocked nasal pathway (nasal obstruction). Risk factors of a blocked nose include the following:

  • Nasal congestion and a "stuffy nose," which can be caused by a cold, sinus infection, or allergies
  • Jaw size and shape
  • Nose size and shape
  • Enlarged tonsils, turbinates, and/or adenoids
  • A deviated septum
  • Benign tissue growths in the nose (nasal polyps) or tumor (rare)
  • Other oral conditions such as crowded teeth

Symptoms of Mouth Breathing

Common signs and symptoms of long-term mouth breathing include the following:

  • Inflamed, red, and swollen gums
  • Poor sleep
  • Chronic fatigue
  • Heavy snoring
  • Morning headaches
  • Sore throat

Possible Oral Health Complications

Mouth breathing is a common symptom of asthma, chronic colds, thumb sucking, nasal septum deviation, or seasonal allergies. It can also be a sign of an underlying oral condition, such as:

Sleep Apnea

A small jaw is linked to sleep apnea, which is a sleeping disorder caused by a blockage in the upper airway while sleeping.

Sleep apnea results in breathing that repeatedly “stops” and “starts.” Common signs of this disorder include mouth breathing, bruxism, and heavy snoring.

Obstructive sleep apnea syndrome (OSAS) is the most common form of sleep apnea. It causes repetitive apneas (no breathing) and hypopneas (shallow breathing) during sleep.

Sleep apnea treatment includes devices, surgery, and therapy. Other forms of treatment include weight loss and nasal decongestants, if necessary. Dentists only treat the obstructive form of sleep apnea. If you have central or complex sleep apnea, you must see a board-certified sleep physician.

Misaligned Teeth

If the teeth in the upper and/or lower jaw are misaligned, mouth breathing may occur. For example, if you have a crossbite or underbite, you are more likely to mouth breathe. This condition can also alter facial growth. If a child has a small upper jaw and mouth breathes, they have an even higher chance of developing a crossbite.

Skeletal Deformities, Improper Facial Growth & Jaw Pain

If your child is a mouth breather, it can alter their face shape and cause irregular jaw positioning.

Improper facial growth can also result in regressed cheekbones, a narrow face (long face), a lower jaw, and/or a low chin.

Mouth breathers commonly have smaller jaws, which leads to crooked teeth and/or a gummy smile. Orthodontic treatment, such as braces or clear aligners, may be necessary.

Dry Mouth & Cavities

Dry mouth, which is when the salivary glands do not make enough saliva to keep your mouth wet, is a common side effect of mouth breathing.

Saliva protects teeth against cavities because it helps wash out plaque and aids in remineralization. Although, if the mouth isn’t producing enough saliva, cavities can form.

Gum Disease

Long-term mouth-breathing habits can dry out the gums and the mouth's tissue lining. Over time, the natural bacteria in your mouth changes, which encourages gum disease.

Gingivitis is a mild form of gum disease that is reversible with professional teeth cleanings. Periodontal disease (PD) is an advanced form of gum disease that results in permanent bone loss and eventually tooth loss.

Speech and Swallowing Difficulties

Swallowing and speech disorders make it difficult to chew food, swallow, and talk normally. Having a hard time breathing after meals is also common, which can result in mouth breathing more often.

Enlarged Tonsils

Some children have adenoids or enlarged tonsils, which can make the airways narrow and results in snoring and paused breathing while sleeping.

If sleeping and breathing patterns are disrupted long-term, serious oral and general health conditions can develop. This includes respiratory tract infections, ear infections, jaw misalignment, sleep apnea, and mouth breathing.

Common Treatment Options

Depending on the cause, treatment for mouth breathing varies.

If the condition is a symptom of sleep apnea disorder or a skeletal deformity, treatment may include:

  • CPAP devices
  • Oral appliance therapy
  • Nasal or throat surgery (minor)
  • Uvulopalatopharyngoplasty (UPPP)
  • Jaw surgery (invasive)
  • Braces or clear aligners, such as Invisalign (teeth misalignment)
  • Jaw repositioning appliances

If mouth breathing is caused by a chronic cold, seasonal allergies, or asthma, treatment may include:

  • Nasal decongestants
  • Antihistamines
  • Prescription steroid nasal sprays
  • A steroid inhaler

Mouth Breathing FAQs

What causes breathing through the mouth?

A blocked nasal pathway causes breathing through the mouth.

This can be temporary and may be linked to a stuffy nose, enlarged tonsils, or tissue growth. It could also be a permanent obstruction such as a deviated septum, jaw or nose shape, or oral condition such as crowded teeth.

What causes mouth breathing at night?

Mouth breathing at night can be caused by temporary nasal pathway obstructions such as a stuffy nose, swollen tonsils, or tissue growths.

It can also be caused by permanent obstructions such as specific nose or jaw shapes, a deviated septum, or oral conditions such as crowded teeth.

What are the side effects of mouth breathing?

Dry mouth, cavities, gum disease, difficulty speaking, skeletal deformities in the face, and jaw pain are all possible side effects of mouth breathing.

How do you fix mouth breathing?

Common mouth breathing treatments include: nasal decongestants, antihistamines, prescription steroid nasal sprays, a steroid inhaler, CPAP devices, oral appliance therapy, nasal or throat surgery (minor), uvulopalatopharyngoplasty (UPPP), jaw surgery (invasive), braces or clear aligners, or jaw repositioning appliances.

Can mouth breathing cause digestive problems?

Mouth breathing may cause aerophagia, where air passes from the stomach to the small intestine. This can cause abdominal bloating, intestinal pain, and excessive belching.

Can mouth breathing cause cough?

Yes, one of the most common side effects of mouth breathing is dry mouth. This can irritate your throat and vocal chords, causing you to cough.

Can mouth breathing cause shortness of breath?

Yes, mouth breathing is a form of over-breathing, which can cause shortness of breath or breathlessness.

Can sleeping with your mouth open cause a sore throat?

Yes, saliva normally keeps your mouth and throat moist. Sleeping with your mouth open can dry your saliva and cause a sore throat.

Can mouth breathing cause dry mouth?

Yes, dry mouth is one of the most common symptoms of mouth breathing.

Is it better to breathe through your nose or mouth?

Breathing through your nose is generally thought of as healthier, as it helps your lungs retain more oxygen. Nose breathing also warms, filters, and adds moisture to the air you breathe.

What is mouth breathing a symptom of?

Mouth breathing is a common symptom of asthma, chronic colds, thumb sucking, sleep apnea, misaligned teeth, skeletal deformities, enlarged tonsils, nasal septum deviation, or seasonal allergies.

Why is it bad to be a mouth breather?

Mouth breathing can cause a number of symptoms, including dry mouth, cavities, gum disease, difficulty speaking, skeletal deformities in the face, and jaw pain.

Last updated on April 7, 2022
4 Sources Cited
Last updated on April 7, 2022
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
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  2. Kahn, Sandra, and Paul R. Ehrlich. Jaws the Story of a Hidden Epidemic. Stanford University Press, 2018.
  3. Motta, Lara Jansiski, et al. “Association between Halitosis and Mouth Breathing in Children.” Clinics, vol. 66, no. 6, 2011, pp. 939–942., doi:10.1590/s1807-59322011000600003.
  4. “Mouth Breathing.” Mouth Breathing - an Overview | ScienceDirect Topics,
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