Mouth Breathing: Why You Shouldn’t Get Used to It and How to Return to Nasal Breathing

“The nose should be considered a true organ. It does much more than simply allow air to pass towards the lungs: it humidifies, warms and filters the air before it reaches the lower airways.

Without exaggerating, we could describe it as the body’s air-conditioning system. The nasal mucosa performs this work continuously and automatically, under the control of the central nervous system through a mechanism known as the nasal cycle, which causes airflow to alternate between the nostrils without us being aware of it,” explains Dr Montemagno.

Nasal breathing is therefore the natural mode of breathing for our respiratory system. Breathing through the mouth means bypassing the functions of the nose and allowing air to reach the lungs at ambient temperature and humidity, with varying levels of pollutants or particles depending on the surrounding environment.

“In most cases, mouth breathing is not simply a habit that developed by chance, nor is it something that can be corrected through willpower alone. More often, it is the consequence of a more or less significant obstruction to airflow through the nose,” the specialist explains.

According to the ENT specialist, the common underlying factor is usually reduced or partially obstructed nasal airflow.

There may be several causes. It can result from inflammation of the nasal mucosa, for example in cases of:

• rhinitis;
• rhinosinusitis;
• persistent nasal congestion.

Alternatively, it may be related to an anatomical condition that narrows the nasal airway, such as:

• deviated nasal septum;
• enlarged turbinates;
• septal perforation;
• nasal polyposis;
• benign lesions;
• malignant nasopharyngeal lesions;
• adenoid hypertrophy in children.

“The key message is this: when mouth breathing becomes habitual, there is almost always an underlying cause, and that cause can be identified,” the specialist emphasises.

Why mouth breathing often becomes worse at night

“Many people notice the problem mainly during sleep, rather than during the day. Sleeping position and relaxation of the tissues can worsen nasal congestion that may be barely noticeable during daytime hours. As a result, a nose that is already partially obstructed may become even more blocked, making mouth breathing almost unavoidable,” explains Dr Montemagno.

This often leads to waking with a dry mouth and the feeling of not having slept properly, even after an adequate number of hours.

“In some cases, nocturnal mouth breathing is also associated with snoring, sleep apnoea and other sleep-related breathing disorders, which require specific assessment. It is not uncommon for a patient to seek medical advice because of snoring and then discover that the underlying problem is impaired nasal breathing that has never previously been investigated,” the specialist adds.

Certain signs can help distinguish occasional mouth breathing from a more persistent underlying problem:

• a nose that feels blocked most of the time;
• frequent mouth breathing, both during the day and at night;
• snoring and episodes of sleep apnoea;
• sleep that never feels truly restorative;
• a very dry mouth on waking;
• difficulty breathing through the nose during physical activity;
• the persistent sensation of never being able to get enough air through the nose.

None of these signs, when considered in isolation, is necessarily a cause for concern. However, the presence of several persistent symptoms over time may indicate a problem that deserves further assessment.

There is no reason to worry about an isolated episode of mouth breathing, for example during a seasonal cold.

However, it is advisable to consult an ENT specialist when mouth breathing becomes frequent, occurs without an obvious trigger, or when comfortable, effortless breathing through the nose no longer seems possible.

“The first step in correcting mouth breathing is always to understand the underlying cause. Identifying the cause generally requires an ENT examination, sometimes including fibre-optic endoscopy, and may be complemented by imaging such as CT and/or MRI of the facial structures and paranasal region.

In the meantime, there are no universal remedies that should be tried independently: it is the diagnosis, rather than self-treatment, that determines the most appropriate management,” the specialist explains.

Treatment depends on the cause of mouth breathing:

• inflammatory conditions, such as rhinitis or rhinosinusitis, can often be successfully treated with medication;
• structural causes, such as a deviated septum, turbinate hypertrophy, nasal polyposis or adenoid hypertrophy in children, may require functional surgery after appropriate specialist assessment.

The goal of surgery is simply to restore effective nasal airflow and allow the nose to perform its normal physiological functions.

A simple everyday comparison can help explain the concept: if the drainage pipe under a sink is bent or blocked, we call a plumber to straighten it or clear the obstruction. In much the same way, the ENT specialist works on the nose by correcting or removing the obstruction so that air can pass through properly again.