Many people grow up hearing that taking deep breaths increases the amount of oxygen in the body. The familiar rule from school still lingers: breathe in through the nose and exhale through the mouth. Yet experts say breathing through the mouth does not serve the body well. Doctor and functional orthodontist Ksenia Pushkina spoke with socialbites.ca to share her insights.
The clinician notes that misaligned teeth and malocclusion are only the tip of the iceberg. Mouth breathing is linked to a broader set of health issues, including adenoids problems, snoring, sleep apnea, persistent nasal congestion, weight gain, poor posture, reduced focus, and heightened anxiety, all connected to how air enters the body.
“Mouth breathing can be more damaging than smoking in effect,” Pushkina explains. People may worry that breathing through the mouth brings in colder air, but the deeper concern lies in the body losing its natural defense – nitrogen monoxide. This molecule is produced primarily when air is inhaled through the nose, which makes it a crucial protective component.
Some people rely on medical masks to guard against germs. According to the expert, the paranasal sinuses perform surprisingly well on their own, aided by nitrogen monoxide.
“Nitrogen monoxide acts as a filter against bacteria and viruses. It activates tiny hairs in the nasal epithelium, helping to clear pathogens from the body, and it dilates blood vessels in the respiratory system to improve oxygen delivery. It also acts as a natural bronchodilator, permeating all body cells, supporting the autonomic nervous system, and aiding recovery by reducing respiratory tract spasms,” Pushkina notes.
Pushkina underscores that keeping the mouth open while breathing deprives the body of oxygen. It may seem counterintuitive, since the mouth can take in more air than the nose, but this is not beneficial in the long run.
“In reality, mouth breathing means not only breathing in too much through the mouth but also exhaling more than needed because the mouth’s opening is larger. While exhaling, significant amounts of carbon dioxide are lost. Carbon dioxide is not a waste gas; it plays a vital role in oxygen release from hemoglobin. Up to 98 percent of the oxygen carried in the blood binds to hemoglobin, and enough carbon dioxide helps oxygen detach and reach every cell. A calm, nasal breath ensures adequate oxygenation,” she explains.
Adenoids, frequent tonsillitis, nasal congestion, and other related conditions often stem from mouth breathing. The oral cavity lacks a natural filter to cleanse incoming air, so when the mouth is open, dirty air reaches the pharyngeal and tonsillar tissues directly. These tissues may respond by enlarging, and repeated mouth breathing can worsen adenoids swelling.
Another factor is the tongue and facial muscles. With the mouth open, the tongue tends to drop downward. The tongue normally presses against the palate, aiding growth and development of the upper jaw. In children, this alignment helps form straight teeth and enhances facial structure; in adults, it supports facial aesthetics and can curb age-related changes.
“When the mouth stays open, these dynamics shift. The tongue no longer supports the palate as it should, and lymph drainage from the tonsils slows. This stagnation can prompt inflammation and worsen breathing. A common paradox is that mouth breathing often leads to a stuffier nose, potentially creating a cycle that requires vasoconstrictor drops to relieve congestion,” the doctor adds.
Snoring and sleep apnea are other consequences of habitual mouth breathing. The effect on sleep can be profound: the heart muscle may not receive adequate blood flow, brain function can be compromised, and the risk of cardiovascular issues rises.
“During snoring, breathing becomes louder and more laborious than necessary. Blood gas balance shifts, and the body periodically nudges you awake to restore balance. Deep, restorative sleep shortens, and mornings can feel brutal as the body fights to recover,” Pushkina emphasizes.
Breathing through the mouth also influences appearance. When breathing is impaired, the tongue’s normal position on the palate is disrupted. The tongue’s proper posture stimulates the upper jaw and supports facial development. In children, this tongue position promotes straight teeth and balanced facial features; in adults, it helps preserve facial aesthetics and can slow visible aging.
“If the mouth remains open, oral breathing becomes the norm and the tongue may droop downward. This shift can lead to facial changes—children may develop downward-growing faces, while adults could notice a double chin, nasolabial folds, and wrinkles,” Pushkina notes.
In summary, the risks of mouth breathing extend beyond daily comfort. Proper nasal breathing supports airway health, oxygen delivery, and facial development, and it can influence sleep quality and long-term well-being. The expert’s guidance highlights a straightforward approach: favor nose breathing whenever possible to support overall health and vitality.
Historically, there have been warnings about inhaling nonstandard vapors. Contemporary medical understanding continues to stress the importance of nasal breathing for maintaining both respiratory efficiency and systemic health.