Nose Breathing vs. Mouth Breathing: Which Is Better?

You’ve probably been told in certain situations to “Breathe in through your nose and out through your mouth,” especially during exercise or meditation or to relax. But have you ever wondered why?

Part of the reason is simple: Breathing through your nose is the most beneficial way to breathe. Pulmonary medicine specialist Jason Turowski, MD, says that it has to do with evolution — and all the little things that happen as we take that breath, from filtering and humidifying the air to releasing nitric oxide.

Humans are naturally designed to breathe through our noses from birth. It’s the way we’ve evolved. “When we’re newborns, we breathe in and out through our noses almost all the time,” Dr. Turowski explains. “This is related to how our throats are configured, so we can breathe and suckle at the same time without choking. It’s a survival mechanism.”

There are good reasons why we continue to default to nasal breathing as we get older, too. To start, inhaling through your nose offers many more benefits to your body than taking in air through your mouth.

Our noses are designed to process the air that comes in very differently than our mouths. These are intentional and functional parts of our body’s design to keep us safe and healthy. So, why do we ever breathe with our mouths?

Why we breathe in different ways

Some people use the term “mouth breather” as an insult, a way of suggesting a person lacks intelligence. It’s a mean thing to say. It’s also wrong. Most people use both their noses and mouths to breathe. And which type of breathing we favor has nothing to do with intelligence.

If you’re more inclined to breathe through your mouth, you may have:

• Congestion issues. We all breathe through our mouth when we’re dealing with allergies, a head cold, sinus issues or run-of-the-mill stuffiness. For some people, nasal congestion is a chronic issue.
• Enlarged adenoids. When these glands, which sit above the roof of your mouth and behind your nose, get swollen or infected, they can block your nasal airways. Adenoids shrink around the age of 7 or 8 and are gone by the time you reach adulthood, but some children can’t wait that long. They have to have their adenoids surgically removed.
• A deviated septum. Whether you were born with it or broke your nose somewhere along the way, a crooked nasal passage can interfere with breathing and cause chronic congestion issues.
• Shortness of breath. Maybe you have asthma or severe acid reflux. Maybe you have an anxiety disorder that leaves you feeling like you can’t take a full breath. Maybe you have a heart or lung condition. Whatever the reason, a person with chronic shortness of breath (dyspnea) may rely on mouth breathing because it moves more air more quickly.

If you don’t have any of these conditions, but inhale through your mouth more often than not, you may want to mention it the next time you’re at your doctor or dentist’s office. (It’s not an emergency unless you’re struggling to breathe.) You may have an underlying condition that, if treated, could make breathing through your nose more comfortable.

Benefits of nose breathing

Here are all the good things your nose does that your mouth doesn’t when you breathe in:

• Controls the air temperature. Your lungs aren’t huge fans of air that’s too hot or cold. Unless you have an obstruction (like a deviated septum or chronic rhinitis), your nasal passageways will warm (and sometimes cool, when needed) the air on its way to your lungs. For example, Dr. Turowski notes that winter runners who breathe deeply through their noses get warmed air without sending a chill to their lungs, versus those who breathe with their mouths.
• Filters the air. The cilia in your nasal passageway filter out debris and toxins in the air and send them directly down your throat instead of into your lungs. Yes, that sounds gross. But it’s better for that crud to end up in your stomach than anywhere else. Mouth breathing sends whatever’s in the air directly into your lungs, which could raise your risk of infection.
• Humidifies the air. According to Dr. Turowski, the passages in your nose are specifically designed to humidify the air you breathe. Your mouth isn’t. That’s part of the reason you occasionally wake up with a dry mouth or a sore throat. Chances are you spent your evening fighting nature by mouth-breathing and didn’t get the humidifying or moisture-balancing benefits of nasal breathing.
• Smells the air. Your nose is the gateway to your olfactory system. Groundbreaking stuff, we know. But a sense of smell is important! Your nose helps you stay safe by detecting harmful toxins in the air and in your food. Sure, you might want to switch to mouth breathing if the friendly neighborhood skunk mists your dog or you’re dealing with hyperosmia. But otherwise, the ability to take a whiff of the world around you is a good thing.
• Receives pheromones. Speaking of smells, your nose plays a critical role in your perception of sex. Perfume, sweat, pheromones: Our ability to smell is key to sexual arousal. Loss of smell (anosmia) can actually lead to a decreased sex drive. That’s right: Mouth breathing can be a real turn off!
• Releases nitric oxide. Nitric oxide (NO) is a chemical our body produces. It’s a vasodilator, meaning it opens up your blood vessels. When our blood vessels are dilated, more blood and oxygen can move through them. The result: Lower blood pressure and better oxygen circulation.
• Limits hyperventilation. It’s incorrect to say that you can never hyperventilate through your nose, but it’s much harder. The reason is simple: You can’t inhale as much air through your nasal passages as you can through your mouth.

Potential side effects of mouth breathing

There are clearly plenty of benefits to breathing in through your nose. But that’s not all. Dr. Turowski says there are also clear downsides to breathing in through your mouth.

Saliva plays a crucial role in our oral health. It keeps our mouths lubricated, protects our enamel, and drowns out harmful materials like sugar and acid. Breathing through your mouth robs your saliva, so all those nasties sit on your teeth longer. That can lead to chronic bad breath (halitosis), gingivitis, cavities and other periodontal problems.

Breathing through your mouth can also cause (or contribute to):

• Snoring or sleep apnea.
• Daytime sleepiness.
• Chapped or cracked lips.
• Drooling.
• Allergies.
• Behavior issues in children.
• Jaw and facial differences.

So, what’s the verdict? Is nose breathing always better?

Dr. Turowski says that if you aren’t living with a health condition that prevents it, there are only two times that you really need to engage in mouth breathing:

• When you need to get more air to your lungs quickly.
• When your nasal passage is blocked due to congestion, allergies or a cold.

You’ll still lose out on those benefits that breathing through your nose provides, but — on those specific occasions — it’s a worthwhile trade.

How to adjust your breathing

If you usually breathe through your mouth and want to change that, Dr. Turowski recommends seeing a healthcare provider. Mouth breathing isn’t our natural default, so there’s frequently a reason you’re doing it. Before you try to make any big changes, it’s best to find out what that reason is. In some cases, mouth breathing simply can’t (and shouldn’t) be avoided.

Let’s say you find out that your mouth breathing is simply a bad habit or a side effect of a condition like anxiety. In those cases, breathwork may help you both break the habit and feel more relaxed. Here are a few techniques to get you started:

• Alternate nostril breathing.
• Diaphragmatic breathing.
• Box breathing.
• 4-7-8 breathing.

Building awareness of your breath can only help you. But other strategies for stopping mouth breathing can be downright dangerous. In particular, Dr. Turowski warns against mouth taping.

If you’re not sure whether your nose breathing strategy is safe, ask a provider’s advice.

Is it ever too late to fix mouth breathing?

When it comes to “fixing” mouth breathing, don’t ask if it’s too late. Ask if the symptoms it’s causing are having a negative impact on your quality of life — and what it would take to correct the problem.

Your answer will depend on what’s causing the issue. If all it’s going to take is adding an over-the-counter allergy treatment to your daily medications, that’s a change worth making. If you’re inhaling through your mouth because your congestive heart failure or chronic obstructive pulmonary disease (COPD) leaves you feeling breathless, your and your provider’s priority will probably be managing the dyspnea, not the mouth breathing.

Is it bad if I keep mouth breathing?

Mouth breathing isn’t ideal, but it isn’t the end of the world either. If you aren’t bothered by symptoms and don’t have any underlying medical conditions that require treatment, changing the behavior is a personal choice.

That said, working with a provider to home in on the cause of your mouth breathing may uncover a health condition you didn’t know you had. And addressing that condition may mean better sleep, drama-free dental appointments, a healthier, happier mindset or fewer days spent coughing and sputtering with allergies. And incorporating breathing exercises into your daily routine is a great way to practice mindfulness and reduce stress.

So, have a conversation with a provider about your breathing. That way, whatever you choose to do, you’ll be making an informed choice.