Mouth Breathing: Causes, Risks, and What Therapy Can Do

Mouth breathing is common—especially during a cold—but habitual mouth breathing (daytime, nighttime, or both) is different. It can be a signal that the nose isn’t doing its job, that sleep and airway are being stressed, or that learned oral–facial patterns have become the “default.”

Here’s the key clinical idea:

Mouth breathing is usually a symptom, not the root cause. The right approach is to identify why it’s happening (structural, medical, behavioral, or neuromuscular), then build a plan that improves airway function, sleep quality, and oral–facial patterns.

Pediatric sleep-disordered breathing ranges from snoring to obstructive sleep apnea, and ENT guidance highlights that disrupted breathing during sleep can have meaningful impacts.
Adenoid hypertrophy is a common pediatric cause of nasal obstruction and is associated with sleep disturbance and mouth breathing patterns.

Quick Take

• Occasional mouth breathing with illness is common. Persistent mouth breathing warrants evaluation.
  
• Common causes: nasal obstruction (allergies, congestion, deviated septum), enlarged adenoids/tonsils in kids, structural airway issues, and learned oral posture habits.
  
• Mouth breathing is associated with snoring and sleep-disordered breathing patterns in many children and adults; sleep evaluation may be appropriate when snoring, pauses, or daytime fatigue are present.
  
• SLPs can help when the pattern involves orofacial myofunctional disorders (tongue posture, lip seal, swallowing patterns) and coordinate care with ENT, dentistry/orthodontics, and sleep medicine.
  

What “mouth breathing” usually means clinically

Two buckets: intermittent vs habitual

Intermittent mouth breathing

• during colds
  
• during heavy exercise
  
• seasonal flares
  

Habitual mouth breathing

• open-mouth posture at rest
  
• sleeping with mouth open
  
• chronic dry lips/mouth
  
• snoring or noisy breathing at night
  
• daytime fatigue or behavioral signs tied to poor sleep
  

Habitual mouth breathing is where clinicians start asking: Is there nasal obstruction? Is sleep impacted? Has posture adapted?

Causes of mouth breathing

1) Nasal obstruction or chronic congestion

Common contributors:

• allergic rhinitis
  
• chronic sinus congestion
  
• turbinate hypertrophy
  
• deviated septum
  
• chronic inflammation

If the nose is blocked, the body chooses mouth breathing—because it must.

2) Enlarged adenoids and tonsils (especially in children)

Adenoid hypertrophy can cause nasal obstruction and sleep disturbance in children and is a classic driver of chronic mouth breathing patterns.
When nasal obstruction is significant or persistent, ENT evaluation is often part of the pathway.

3) Sleep-disordered breathing and airway instability

Snoring, restless sleep, witnessed pauses, and daytime sleepiness/behavioral concerns can indicate sleep-disordered breathing. ENT Health describes pediatric sleep-disordered breathing as a spectrum from snoring to obstructive sleep apnea (OSA).
In adults, mouth breathing can co-occur with OSA and nasal obstruction. The “right” next step often involves sleep medicine evaluation.

4) Orofacial myofunctional patterns (learned posture + muscle function)

Some people develop:

• low tongue resting posture
  
• open-mouth resting posture
  
• weak lip seal
  
• tongue thrust swallow patterns
  

ASHA describes orofacial myofunctional disorders (OMDs) as deficits involving oral and orofacial muscles that can interfere with growth, function, or development.
In these cases, mouth breathing treatment is not just “breathe through your nose.” It’s a retraining plan—paired with medical evaluation when obstruction is present.

5) Habit and environment

• prolonged pacifier/thumb use (in some cases)
  
• chronic dry air
  
• low sleep quality → mouth open posture at night
  
• poor nasal hygiene routines
  

Habit alone is rarely the full story—but it can maintain the pattern after the original trigger resolves.

Risks of chronic mouth breathing

1) Sleep quality and sleep-disordered breathing risk

Mouth breathing frequently co-occurs with snoring and sleep-disordered breathing symptoms. Pediatric sleep-disordered breathing is associated with health and behavioral impacts, and improved screening/management can benefit long-term outcomes.

Practical red flags:

• snoring most nights
  
• witnessed pauses/gasping
  
• restless sleep, sweating
  
• daytime sleepiness, morning headaches
  
• ADHD-like behaviors that worsen with poor sleep

2) Oral health and dryness burden

Common downstream effects:

• dry mouth, chapped lips
  
• increased irritation of gums/throat in some people
  
• higher discomfort with orthodontic appliances

3) Oral–facial growth and function (kids)

Chronic nasal obstruction and mouth breathing are discussed in clinical literature as associated with altered facial growth patterns in some children, especially when driven by adenoid hypertrophy and chronic obstruction.
This doesn’t mean “mouth breathing causes facial changes in everyone,” but it does justify earlier evaluation when the pattern is persistent.

4) Speech and feeding/swallow patterns

Mouth breathing often co-occurs with:

• tongue thrust swallow patterns
  
• reduced tongue-to-palate resting posture
  
• articulation distortions in some profiles (case-dependent)
  
• messy eating or inefficient chewing in some children

This is where SLP evaluation can be particularly useful.

Decision Rules: When to act

Monitor briefly if

• symptoms occur only during a cold
  
• nasal breathing returns fully between illnesses
  
• no snoring, no sleep concerns

Schedule evaluation soon if

• open-mouth posture is frequent during the day
  
• mouth is open most nights
  
• persistent snoring
  
• chronic dry mouth/lips
  
• dental/orthodontic concerns about posture or oral habits
  
• speech, feeding, or swallow patterns suggest OMDs

Seek medical evaluation promptly if

• witnessed pauses/gasping during sleep
  
• significant daytime sleepiness or behavioral changes tied to sleep
  
• failure to thrive/poor growth (kids)
  
• recurrent infections or significant nasal obstruction

Symptom → Action Map

What therapy can do

This is where many families get bad advice (“just close your mouth”). Effective therapy is targeted and coordinated.

1) Identify whether the pattern is obstructive, functional, or both

Therapy should start with:

• history and symptom pattern
  
• observation of resting posture (lips, tongue)
  
• nasal vs oral airflow behaviors
  
• swallow patterns (tongue thrust, compensations)
  
• sleep symptoms screening and referral triggers
  

SLPs working in this area often coordinate with ENT, dentistry/orthodontics, and sleep medicine.

2) Orofacial myofunctional therapy (when appropriate)

ASHA’s OMD guidance supports the role of SLPs in assessment and treatment of orofacial myofunctional disorders.

Common therapy targets:

• lip seal at rest
  
• tongue resting posture (tongue-to-palate contact where appropriate)
  
• nasal breathing habits (when obstruction is ruled out/managed)
  
• swallow pattern retraining (reducing tongue thrust where relevant)
  
• functional carryover: meals, sleep routine, daytime posture

3) Behavior and environment plan

High-yield components:

• nasal hygiene routine (as medically appropriate)
  
• sleep positioning and routine strategies
  
• trigger reduction (dry air, allergens, habit loops)
  
• caregiver coaching for consistent cues (without nagging)

4) Airway team coordination

Therapy is not a substitute for:

• evaluating nasal obstruction
  
• treating allergies medically
  
• addressing enlarged adenoids/tonsils when indicated
  
• evaluating OSA

The best outcomes happen when therapy is the “functional retraining arm” of a coordinated airway plan.

What progress looks like

Instead of “mouth breathing stopped,” track measurable changes:

• increased nasal breathing time during calm activities
  
• closed-lip resting posture more often
  
• reduced morning dry mouth
  
• reduced snoring / improved sleep continuity (when airway drivers are addressed)
  
• improved tongue posture consistency
  
• better swallow pattern efficiency (less tongue thrust)
  

Progress should be gradual and sustainable, not forced.

What to ask your provider

1. Is there nasal obstruction (allergies, adenoids, structural issues) driving this pattern?
   
2. Are there signs of sleep-disordered breathing that warrant ENT or sleep testing?
   
3. Does the child/adult show an orofacial myofunctional disorder pattern that therapy can address?
   
4. What are the top 2 therapy targets for the next 6 weeks?
   
5. How will we measure change (posture, symptoms, sleep, swallow function)?

If you’re searching “speech therapy near me”

If mouth breathing is paired with tongue posture, swallow pattern, speech sound issues, or sleep-related airway concerns, look for a speech-language pathologist with experience in:

• orofacial myofunctional disorders (OMDs)
  
• coordination with ENT/sleep/dental teams
  
• pediatric and adult airway-focused care (as applicable)
  

Virtual speech therapy can support habit training and caregiver coaching in some cases, but airway obstruction and sleep disorder evaluation require medical assessment.

Where BreatheWorks fits

BreatheWorks is a speech-language pathology practice with a whole-patient approach that supports patients from infancy through geriatrics. Care may include speech/voice, feeding/swallowing, orofacial myofunctional therapy (OMT/OMD), and TMJ, with an emphasis on root-cause assessment across areas like sleep and breathing when relevant. You can start with in-person care at a clinic or choose secure virtual therapy with the same patient-centered model.

FAQ: Mouth Breathing 

What causes mouth breathing?

Common causes include nasal obstruction (allergies/congestion/structural issues), enlarged adenoids in children, sleep-disordered breathing, and learned oral posture patterns.

Is mouth breathing bad?

Persistent mouth breathing can be associated with sleep disruption, oral dryness, and in some children may be linked with chronic nasal obstruction and growth/function concerns—so evaluation is recommended when it’s habitual.

How do I know if my child’s mouth breathing is from adenoids?

Adenoid hypertrophy commonly causes nasal obstruction and sleep disturbance in children; an ENT evaluation can assess this and guide treatment options.

Can a speech-language pathologist help with mouth breathing?

Yes—when mouth breathing is part of an orofacial myofunctional disorder pattern (tongue posture, lip seal, swallow patterns). SLPs assess and treat OMDs and coordinate with medical providers when obstruction is present.

Is mouth breathing linked to snoring or sleep apnea?

Mouth breathing frequently co-occurs with snoring and sleep-disordered breathing symptoms; persistent snoring or observed breathing pauses warrants medical evaluation.

What is “mouth breathing treatment”?

Treatment depends on the cause. It may include medical management of nasal obstruction, ENT intervention for adenoids/tonsils when indicated, and therapy to retrain oral posture and nasal breathing habits when appropriate.