The Link Between Mouth Breathing and Brain Function

The brain is complicated. And healing the brain can be equally complicated. But if your child is suffering from a condition where brain inflammation is affecting their health and behavior, it’s important to focus on the basics of brain health as you’re exploring solutions.

That’s why we’ve been spending some time focusing on the foundations—food, water, and air. We’ve talked about food and water. Now it’s time to talk about air, specifically mouth breathing.

The Role of Oxygen and Mouth Breathing in Brain Function

Oxygen is critical for brain use, growth, and healing. In fact, the brain uses a full 20% of the body’s oxygen intake, three times as much oxygen as the muscles in the body. But it’s not just about getting enough oxygen.

How you breathe plays a crucial role in how effectively that oxygen reaches the brain and supports its function. There’s a difference between breathing through your nose and breathing through your mouth.

Mouth breathing can limit the brain’s access to oxygen in ways that impact behavior, learning, and mental health.

How Your Child’s Breathing Habits Impact Brain Health

Recent research has linked mouth breathing to cognitive deficits, including declines in memory and learning ability. Animal studies have shown that mouth breathing causes changes in the central nervous system, while human studies have found that children who breathe orally struggle with working memory tasks.

Chronic mouth breathing can have significant consequences on brain function and overall well-being. It activates the body’s stress response, keeping the nervous system in fight-or-flight mode, which can contribute to anxiety and difficulty focusing.

Even seemingly minor symptoms—like irritability, restlessness, or inconsistent focus—may be signs that your child’s breathing patterns are affecting their brain.

Studies have linked mouth breathing to a higher risk of ADHD, memory impairment, and cognitive challenges. In contrast, nasal breathing has been shown to support brain function, improve memory, and enhance mood.

In contrast, nasal breathing has been shown to support brain function, improve memory, enhance mood, and support emotional regulation. It encourages the body to remain in a parasympathetic (rest-and-digest) state, which is essential for healing and focus.

(Explore how serotonin plays a role in children’s anxiety for deeper insight.)

One reason for this is how oxygen reaches the brain. Deep, belly breathing helps oxygen reach the lower lungs, where the most blood circulation and oxygen exchange can occur. Mouth breathing, on the other hand, limits oxygen delivery by reducing carbon dioxide and nitric oxide levels, which are essential for proper blood flow to the brain. Nasal breathing results in more activation and connection in the brain than oral breathing.

Why Nasal Breathing Makes a Difference

One reason nasal breathing is so important is because of how oxygen reaches the brain. Deep, belly breathing helps oxygen reach the lower lungs, where the most blood circulation and oxygen exchange occur. This maximizes oxygen delivery to the brain and other organs.

Mouth breathing, on the other hand, disrupts this process. It limits oxygen intake and reduces levels of carbon dioxide and nitric oxide—two gases that are crucial for blood vessel dilation and brain oxygenation. Without proper levels of these gases, the blood flow to the brain is compromised, which can impair cognitive function.

This is why children who mouth breathe often experience brain fog or mental fatigue. Their brains simply aren’t receiving the oxygen they need to function optimally.

Nasal breathing stimulates nitric oxide production, which helps relax blood vessels and allows more efficient oxygen transport. It also helps filter and humidify the air, reducing irritation and inflammation in the respiratory system.

Fixes for Chronic Mouth Breathing

If your child breathes through their mouth regularly, there are several effective strategies to help retrain nasal breathing and improve oxygenation.

Biological Dentistry

Mouth breathing can sometimes be linked to structural issues in the mouth and jaw, such as a narrow palate or misaligned teeth. Biological dentists assess oral development and airway health, looking for underlying causes of mouth breathing. Addressing these structural issues early can support better breathing patterns, as well as long-term oral health.

Palate Expansion

A high, narrow palate can restrict airflow, making nasal breathing more difficult. Palate expansion—often done with a specialized orthodontic appliance—widens the upper jaw, creating more space for the tongue and improving airflow through the nasal passages. This is especially helpful for children whose palates are still developing.

Many parents notice that once palate expansion begins, their children start sleeping better and show improvements in mood and attention—signs that better oxygen flow is already benefiting the brain.

Myofascial Therapy (Tongue Placement)

Proper tongue posture plays a crucial role in breathing. When the tongue rests against the roof of the mouth, it supports the airway and encourages nasal breathing. Myofascial therapy helps strengthen tongue and facial muscles, retraining proper placement to make nasal breathing easier and more natural.

Nasal Breathing Training

Just like any other habit, breathing patterns can be retrained. Nasal breathing exercises, such as slow, controlled breathing through the nose, can increase oxygen efficiency and strengthen the nasal passages. Some techniques, like Buteyko breathing, focus on improving CO2 tolerance and reducing over-breathing, which can help make nasal breathing feel more natural.

Incorporating these exercises into a daily routine—even for a few minutes—can begin to shift a child’s default breathing pattern from mouth breathing to nose breathing, which in turn helps regulate their nervous system and support brain development.

Mouth Taping at Night

For those who breathe through their mouth while sleeping, mouth taping is an option. A small piece of gentle, hypoallergenic tape over the lips encourages nasal breathing overnight. Proponents of mouth taping suggest that it may improve oxygenation, reduce snoring, and support better sleep quality. However, research on this practice is still limited, and further studies are needed to fully understand both its potential benefits and risks.

By addressing the root causes of chronic mouth breathing and implementing these strategies, you can help your child develop healthier breathing patterns—leading to better focus, improved mood, and enhanced brain function.

Supporting Long-Term Brain and Nervous System Health

Mouth breathing may seem like a small thing, but its impact on the brain is anything but small. By addressing chronic mouth breathing early—especially in children—you support not just their physical development, but also their learning capacity, emotional regulation, and long-term brain health.

Even if your child doesn’t currently show severe symptoms, early signs of mouth breathing—like sleeping with an open mouth, dry lips, or frequent snoring—are worth addressing.

Children who breathe better often sleep better, focus more easily, and feel calmer in their bodies. All of this creates the conditions for healing, growth, and thriving—especially when dealing with conditions that involve neuroinflammation or developmental delays.

By looking at something as simple as how your child breathes, you’re laying the foundation for powerful, lasting change. And if you’re addressing brain inflammation, understanding high glutamate may offer additional clarity.

In the next blog, we’ll take a look at how sinus health affects the brain.