Why Breathing Through Your Mouth Is Ruining Your Health

While it may seem like a harmless habit, chronic mouth breathing can lead to serious oral health issues and permanent facial changes.

Breathing through the nose is a natural, preferred way of breathing. But, does everyone actually breathe through their nose? The answer is “no”. 

Many people regularly breathe through their mouths. While mouth breathing may seem harmless, this habitual breathing can lead to a wide range of health problems.

What Is Mouth Breathing?

Mouth breathing occurs when a person breathes consistently through the mouth rather than the nose. This may happen during the day, at night, or both. 

It usually occurs when airflow through the nose is restricted. Chronic habits or several underlying medical reasons can cause this condition:

• Nasal congestion
• Allergies
• A deviated nose septum
• Enlarged tonsils
• Sleep apnoea

The Hidden Harms of Mouth Breathing

When mouth breathing becomes chronic, it can have many negative effects on the body.

Poor oral health

Breathing through the mouth dries up the oral cavity and reduces saliva production. Saliva is vital to neutralise acids and protect the teeth and gums.

Without adequate saliva, dry mouth becomes an ideal environment for bacteria to thrive. This increases the risk of tooth cavities, gum disease, and bad breath.

 

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Facial changes

Habitual mouth breathing, especially in children, can interfere with normal facial growth. This is often referred to as a “mouth-breathing face”.

Possible facial changes include:

• A long and narrow face
• Misaligned teeth (e.g. overbite or underbite)
• A narrow palate, which can affect chewing and speech
• Droopy eyelids

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Adults who are chronic mouth-breathers may also experience accelerated facial ageing symptoms, such as:

• Increased wrinkles around the lips and chin
• Sagging cheeks
• Dry skin around the mouth and lips 
• A less-defined jawline (a softer and rounded lower jaw)
• Reduced skin elasticity

Reduced oxygen delivery

The nose is designed to filter, warm and humidify the air we breathe in. This process improves oxygen absorption in the lungs. 

Meanwhile, mouth breathing bypasses this natural mechanism. This makes the dry, unfiltered air less efficient in delivering oxygen to the lungs. Poor oxygen delivery increases fatigue during the day, even after a full night rest. 

Increased risk of infections

The nose protects the airway and the lungs by filtering out bacteria, dusts and allergens. 

Breathing through the mouth allows unfiltered air to go directly into the lungs. This increases the risks of upper respiratory infections, sore throats and worsening asthma symptoms. 

Postural Strain 

Mouth breathing often leads to a forward head posture, as mouth-breathers subconsciously adjust their head position to keep the airway open. 

Over time, this can contribute to:

• Neck and shoulder pain 
• Poor posture
• Jaw tension 

Ways to Encourage Nasal Breathing

Now, you know the harms of mouth-breathing! So, let’s see some helpful steps to breathe in the right way: 

• Practise nasal breathing
• Manage allergies or nasal congestion
• Optimise sleep position to prevent restricted airway

See an ENT (ears, nose and throat) specialist as soon as possible if you have a deviated nasal septum or persistent nasal block. 

Key Takeaways

Mouth breathing is more than just a habit. It is a health issue that can affect oral health, sleep, facial structures, and overall well-being. 

See a doctor if you experience on-going symptoms:

• Dry mouth after waking up
• Bad breath
• Snoring 
• Drooling during sleep
• Persistent daytime fatigue

References

1. Mouth Breathing. Cleveland Clinic. Updated: 23 July 2025. https://my.clevelandclinic.org/health/diseases/22734-mouth-breathing
2. How To Sleep with a Blocked Nose? Medical Channel Asia. Updated: 28 November 2025. https://medicalchannelasia.com/sleep/how-to-sleep-with-a-blocked-nose/
3. Tired All Day? Sleep Apnoea May Be The Reason. Medical Channel Asia. Updated: 21 December 2025. https://medicalchannelasia.com/sleep/sleep-apnoea-guide/
4. How Mouth Breathing Accelerates Facial Aging: Key Impacts Explained. Sleep and Sinus Centres. Updated: 30 August 2025. https://sleepandsinuscenters.com/blog/how-mouth-breathing-accelerates-facial-aging-key-impacts-explained
5. The Best Sleep Positions For Better Rest. Medical Channel Asia. Updated: 22 December 2025. https://medicalchannelasia.com/sleep/the-best-sleep-positions-for-better-rest/