Everyone has a stuffy nose due to colds or seasonal allergies. Nothing too serious, if the situation doesn’t last long: you resign yourself to breathing through your mouth. However, not everyone knows that the mouth and nose are not the same thing when it comes to breathing. And when chronic nasal congestion and obstructions, or bad habits lead to breathing preferably with the oral cavity, problems begin. It is in fact a habit that exposes you to several important long-term health dangers, some of which are quite unexpected.
How common is it?
In medical terms, breathing preferentially with the mouth is defined as oral breathing, and is defined by a percentage greater than 25-30 percent of the air inhaled coming from the oral cavity, rather than from the upper respiratory tract (the nose). It is a relatively common problem among the little ones: there is no certain data, but research speaks of a percentage of between 10 and 50 percent of children under 8 years of age who breathe regularly through their mouth, especially during sleep.
It tends to resolve naturally with age, but can remain a long-term habit in the presence of upper airway obstructions, chronic rhinitis, and even in the case of postural defects that make it difficult to breathe in through the nose. Furthermore, breathing through the mouth induces a vicious circle, which leads to a sort of “atrophy”, or lack of habit, of using the nose to inhale, and increases the probability of inflammation of the adenoids and tonsils, which further narrow the space available to breathe through the nose.
What problems does it cause?
The nose is the organ developed by our species for breathing. And this is why, although possible, breathing in through the mouth is not optimal. First, the air that passes through the nose is heated, humidified and filtered by the cilia and mucus present in the airways, which trap allergens, pollutants, dust and pathogens, preventing them from reaching the lungs. When you breathe through your mouth, all these pathogens and irritants first reach your tonsils and then your lungs, facilitating inflammation and infection.
That’s not all, because the nose also offers another advantage: it provides nitric oxide, a colorless and odorless gas produced by the paranasal sinuses, which is mixed with oxygen during nasal breathing, and once it reaches the lungs improves absorption of oxygen in the pulmonary alveoli, increases blood oxygenation, and acts as a vasodilator, improving blood pressure. However, all these benefits are drastically reduced in the case of excessive oral breathing.
Morphological and cognitive changes
Regular mouth breathing from childhood can induce postural and morphological changes throughout development. There is a theory, known as “Moss’ functional matrix theory”, according to which nasal breathing is fundamental for a balanced development of craniofacial structures. According to some specialists, it is possible that oral breathing induces the appearance of characteristic somatic features, such as a narrow face and mouth, dental malocclusions, the so-called gingival smile (or pony, i.e. a smile that also reveals part of the gums), a receding chin.
More recently, the possibility that mouth breathing reduces the cognitive abilities of our species has been raised. A study from Gachon University in Korea analyzed the brain activity of 22 healthy adults who took part in a memory test carried out first by breathing through their nose and then through their mouth. The results demonstrated greater activation of brain structures, and greater connection of the same, during nasal breathing. A detail that would lend credence to another eventuality often cited in this area, namely that children affected by oral breathing show a general lack of energy, with symptoms such as hypoactivity, drowsiness, listlessness, poor academic and sporting performance.
What to do?
Obviously, in most cases to resolve oral breathing problems it is necessary to treat the disorders that cause them: nasal polyps, chronic congestion of the upper airways, deviations of the nasal septum, and much more. It is therefore the task of paediatricians, and even more often of dentists (usually among the first to notice the problem when the causes are morphological), to recognize the symptoms and identify a treatment strategy. For our part, what we can do is keep in mind the health problems that can arise from chronic oral breathing, and therefore not underestimate apparently trivial problems, such as frequent pharyngitis or rhinitis or a deviated nasal septum, which can practically always be easily resolved with the right attention from a doctor.
For the rest, what experts advise is to always try (unless it is really impossible) to reduce involuntary mouth breathing to a minimum. To do this, it may be enough to pay attention to how you breathe, and actively try to breathe mainly through your nose. For adults it is also possible to use adhesive tape (possibly designed for medical use) with which to close the mouth to mechanically prevent oral breathing, and retrain the breathing that passes through the nose. There are those who recommend it even during the night hours, but as always it is better to ask the opinion of your doctor before embarking on dangerous DIY activities in the health field.