Mouth Breathing: Causes, Side Effects, And Treatment

Do You Have A Mouth Breathing Problem?

Mouth breathing is a habitual respiration through the mouth instead of the nose. It appears harmless, unassuming, and unsuspecting form of breathing. Though it  is perfectly natural to breathe through your mouth at certain times, such as exercising. But, breathing through the mouth most of the time, however, can have debilitating affects on your health.

These problems can be especially severe for children due to it’s implications on their dental and facial growth. Children whose mouth breathing is untreated may develop crooked teeth, and long and narrow faces.

Nose Breathing Vs Mouth Breathing

Nose breathing is the correct and the most optimal way to breathe. An important function of the nose is the preparation of the atmospheric air for use by the lungs. The nose cleans, moistens and warms the inspired air.

Failure to do so, i.e. by breathing through the mouth instead of the nose, has been considered to be injurious to the tissues lining the respiratory tract and oral cavity because of the impact of cold, dry and dirty air.

Not only are our bodies designed for nose breathing based on the specific apparatus and the mechanisms, by which we inhale and exhale through nose breathing, but there are numerous health benefits from correct consistent nose breathing. Mouth breathing bypasses important stages in the breathing process. Thus, this way of breathing leads to many health problems.

Are The Causes Of Mouth Breathing?

Mouth breathing is a postural habit that can develop for numerous reasons. Below are the most common reasons:1

1. Obstructive – Nasal Congestion

Nasal congestion has a variety of causes, and is usually attributed to either a structural anatomic blockage or swelling of the nasal tissue. Both problems can narrow the nasal cavity and give a sensation of “nasal congestion”. The following is a list of potential causes of nasal congestion which may lead to mouth breathing:


Allergies may lead to nasal obstruction. When a nasal obstruction is present, it is common to unconsciously breath through the mouth instead of the nose. Nasal airway obstructions block the nasal passages and prevent a normal, comfortable amount of air from passing through the nose. Any obstruction in the nasal cavity can be a source of discomfort and can have a significant impact on daily life.2

style="text-align: justify;">Respiratory Infection

Upper Respiratory Infections (URIs) are among the most common reasons for nasal congestion. Another name for this condition is the “common cold”. This can lead to mouth breathing, due to obstructed nasal passages.

Antrochoanal Polyps And Swollen Tonsils

Specific causes that have been linked to mouth breathing include, antrochoanal polyps which are benign lesions in the nose, that may cause an obstruction during normal nose breathing. Enlarged tonsils and adenoids, can also obstruct the nasal breathing system.

2. Anatomic Causes

Structural Abnormalities

Nasal obstruction can occur due to anatomic abnormalities of normal structures in the nose. The nasal septum is the wall that separates the two sides of the nose, and consists of cartilage and bone. Septal deviation, or a “crooked septum”, may cause a narrowed airway and difficulty in breathing through the nose.

3. Habitual Causes

Some individuals breathe through their mouth through force of habit,

perhaps due to a previous cause of nasal obstruction that is now corrected.

Each of these factors make it physically impossible for a person to nasal breathe. If nasal breathing is not possible, the body’s only choice is to mouth breathe.

What Are The Adverse Health Effects Of Mouth Breathing?

1. Facial Growth And Development

Breathing through your mouth can actually change the shape of your face and alter your appearance. This is especially true for children because they are still growing. Children whose mouth breathing goes untreated may suffer from abnormal facial and dental development, such as long, narrow faces and mouths, gummy smiles, gingivitis and crooked teeth.

2. Sleep Disorders And Sleep Apnea

Studies have shown that upper airway obstruction/mouth breathing can cause sleep disorders and sleep Apnea. Studies also reflect that children with sleep disorders have problems paying attention in school, are often tired, and may exhibit behavior problems.

Many of these children are often misdiagnosed with Attention Deficit Hyperactivity Disorder (ADHD). The ideal treatment for these children involves treating the blocked airway, allowing the child to breathe through the nose rather than the mouth.3

style="text-align: justify;">3. Postural Changes

Mouth breathing causes posture changes as well. In order to open the airway, the head rests in a forward position and the shoulders slump. This is unhealthy for the spine.

4. Oral Health

Mouth breathing has serious effects on the development of the facial skeleton and the occlusion of the teeth because of the displacement of normal labial, buccal and lingual muscular forces.

The resting posture of the lips and position of the tongue due to mouth breathing have also been shown to cause problems with the orthodontic treatment. Thus, the time spent in braces can be extended, and the chance for relapse after the braces are removed is higher.

5. Other Effects On The Body

Using the mouth for breathing disrupts our natural body mechanics. It can affect a number of bodily functions and lead to symptoms such as:4

  • Headaches
  • Gingivitis and Gum disease
  • Sore throat
  • Cold symptoms
  • Bad breath
  • Higher risk for cavities
  • Poor sleep — leading to chronic fatigue
  • Digestive disturbances — gas, upset stomach, acid reflux, etc.
  • Medical issues – Blood pressure and Heart problems

These problems are caused mainly due to oxygen deprivation. When we take in air through the mouth, less oxygen is able to be absorbed into the bloodstream. Poor oxygen concentration in the bloodstream has been associated with various medical issues.5

What Can Be Done To Treat Mouth Breathing?

Treatment for mouth breathing is available and can be beneficial for children if the condition is caught early. A dentist can check for mouth breathing symptoms and swollen tonsils.

If tonsils and/or adenoids are swollen, they can be surgically removed by an ear-nose-throat (ENT) specialist. If the face and mouth are narrow, dentists can use expansion appliances to help widen the sinuses and open nasal airway passages.


In order to stop mouth breathing, the muscles must be “re-trained” to function in new ways. A myofunctional therapist can also be an instrumental figure in helping you learn to breathe in a healthy way. Myofunctional therapists are skilled, at helping children and adults, gain control over muscle patterning habits, including those involved in mouth breathing.6

It is, thus, important to screen and diagnose for mouth breathing in adults and in children as young as 5 years of age. If mouth breathing is treated early, it’s negative effect on facial and dental development and the medical and social problems associated with it can be reduced or averted.

Since at this time, many health care professionals are not aware of the health problems associated with mouth breathing. If you or your child suffers from this condition, speak with a health care professional who is knowledgeable about mouth breathing.