Conscious Breathing

Think about the last time you woke up with a dry mouth. It's often the sign of hours spent breathing through it, with nothing to catch the water on its way out.

Your nose works differently. As warm air leaves your lungs, it passes over the cooler lining of your nose, and some of the moisture stays behind. On your next breath in, that moisture goes back into the air before it reaches your lungs.

Breathe through your mouth and you skip that step. The air reaches your airways unconditioned, drying and irritating them.

A Swedish team measured how much water that costs. The same volunteers, at rest, moved almost the same amount of air each minute through both routes. The only thing that changed was the way out, and that alone was enough for the mouth to lose more water.

Water is only one part of the story. Read "10 Powerful Reasons to Breathe Through Your Nose" in our CO₂ Academy. Link in bio.

Love that you read this far. Sources below, searchable by name or PMID at pubmed.gov:
-2006: "Increased net water loss by oral compared to nasal expiration in healthy subjects" (Svensson et al.), PMID 16550955

A child's face is still growing, and the way your child breathes helps steer that growth. Nose breathing supports the tongue posture that helps the upper jaw grow forward and outward.

Chronic mouth breathing can lead to a high palate, a receding chin, crowded teeth, and narrower airways.

Because so much of this growth happens in childhood, the sooner nose breathing is restored, the better for your child's jaw, bite, posture, and lifelong airway health.

Want to learn more? Join the Conscious Breathing community. Link in bio. 🫁

Progesterone does more than its name suggests. After ovulation it climbs, your breathing rises with it, and the level of CO₂ in your blood drops slightly as a result.

Most months, that is nothing you notice. But if your baseline breathing already runs a little high, the same monthly drop can push you past the point where you start feeling premenstrual symptoms.

Researchers saw it in a small study of three women with severe premenstrual symptoms. After ovulation, the CO₂ in their breath fell by 12 to 18 mm Hg on average, much further than in healthy women, and their symptoms came with it. When medication stopped progesterone from rising, the CO₂ drop did not happen and the symptoms did not appear either.

In another study with 28 women, those tested after ovulation had significantly lower arterial CO₂ than those tested before.

Slow, low, rhythmic breathing through the nose is a simple tool you can use to gently build CO₂ tolerance over time, and it may help you ease premenstrual symptoms.
Love that you read this far. Sources below, so you can look them up yourself:

-2001: "Physicochemical analysis of phasic menstrual cycle effects on acid-base balance" (Preston et al.), DOI 10.1152/ajpregu.2001.280.2.R481
-2006: "Symptoms of premenstrual syndrome may be caused by hyperventilation" (Ott et al.), DOI 10.1016/j.fertnstert.2006.01.062

Eight rooms, eight different audiences, one thread connecting them: a gas most people have never once thought about.

CO₂ decides how oxygen reaches your cells, how blood flows, how well you sleep, and how your nervous system settles or doesn't.

This autumn, our founder Anders Olsson has been in the room with doctors, athletes, and investors, all asking the same question: how do we use the science of breathing to perform and live better?

Some of those conversations have already happened. A few more are still ahead, and you can be in the room too.

At select events, we're bringing the Cardihaler and Cardisuit so you can try them yourself.

Several of these are open to the public; check each event's own website for tickets and registration.

For a long time, we've wanted a place for all of us.

Every week, people write to us with questions and stories. A few of the discussions make it into our FAQ or testimonials page. Most stay between two people, and nobody else gets to add what they know.

Many of you are in our Facebook and Instagram groups. They help, but a good conversation there competes with the noise of social media.

This weekend we opened the Conscious Breathing Community. It's a quiet place of our own, free to join, built around what we care about: breathing and CO₂, sleep, stress and anxiety, health, performance, the science, and the upcoming book, CO2 The Master Regulator.

Here, the person asking about sleep can talk to the person who already solved it.

We've opened a few groups around the topics you ask about most. As a member, you can join regular Q&A sessions for free.

The rest is undecided, on purpose. Which groups we add and where the conversations go will be shaped by the members.

Come in and look around. Share your health challenges, your health vision, your experience.

A personal note. To me, Conscious Breathing is a path to a kinder and calmer inner voice, slightly wiser decisions, and a willingness to help others. It's a lifestyle with no exit strategy. I believe we are here to help each other grow, and we do that by sharing what we know. None of us stays well alone.

Anders

The cleaning cycle is not only nocturnal.

In 2025, a research team led by neuropsychologist Sephira Ryman found that brief, controlled increases in CO₂ inhaled while awake stimulated glymphatic clearance in both healthy adults and people with Parkinson's disease. :brain:​

Nobody in that study was asleep. That does not make sleep optional, since the channels only widen during deep sleep. It shows the CO₂ signal does real work on its own, awake or asleep.

Light, fragmented sleep keeps the dishwasher running at reduced capacity all night. A mouth that falls open vents the CO₂ the cycle depends on. Neither stops the cleaning. Both slow it down.

Everything that supports deeper, more stable sleep supports the cleaning cycle: nasal breathing during the day, regular low-intensity movement, a calm and healthy nervous system.

Breathing retraining and exercise through the nose also help, by building the CO₂ response the brain appears to need, day and night.

Your brain never got drainage. It got a window instead, and every good night opens it.

Save this if you wake up with a dry mouth, and send it to someone whose nights come in pieces.

Love that you read this far. Sources below, so you can look them up yourself:

-2012: "A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid beta" (Iliff et al.), DOI 10.1126/scitranslmed.3003748
-2013: "Sleep drives metabolite clearance from the adult brain" (Xie et al.), PMID 24136970
-2014: "Pathophysiology of human ventilatory control" (Dempsey and Smith), DOI 10.1183/09031936.00048514
-2025: "The influence of intermittent hypercapnia on cerebrospinal fluid flow and clearance in Parkinson's disease and healthy older adults" (Erhardt et al.), PMID 41271795
-2026: "The glymphatic system clears amyloid beta and tau from brain to plasma in humans" (Dagum et al.), DOI 10.1038/s41467-026-68374-8

Most people assume emotion shapes breathing, you breathe fast when you're afraid, slow when you're calm. A study suggests breathing can evoke emotion too.

Psychologist Pierre Philippot, at the University of Louvain, asked volunteers to evoke a specific emotion, joy, anger, fear, or sadness, then describe how they were breathing while they felt it.

The patterns held up consistently from person to person: joy produced low, slow, regular nasal breathing. Anger produced fast, big, irregular nasal breathing. Fear produced fast, shallow, irregular breathing, with the highest chest tension of any emotion. Sadness produced moderate, nasal breathing, with more sighs and tremors than any other emotion.

Philippot then flipped the experiment. A new group of volunteers was given a breathing pattern to follow, with no mention of emotion at all, disguised as a study on breathing and heart health, complete with a blood pressure cuff that wasn't actually recording anything. Not one of them guessed what was really being tested.

The joy pattern lifted mood. The anger pattern produced anger, and some fear. The fear pattern produced a mix of fear and anger. The sadness pattern was the one that did not hold, some people felt sad, and others felt good.

With no memory, no imagined scene, and no story involved, breathing accounted for roughly 40% of the emotional shift researchers measured, more than three times what changing someone's facial expression alone typically produces in similar experiments.

This is a glimpse from Anders Olsson's new book, The Master Regulator. Download a free chapter now, link in bio.

Love that you read this far. Sources below, so you can look them up yourself:

-2002: "Respiratory feedback in the generation of emotion" (Philippot et al.), DOI: 10.1080/02699930143000392

The Relaxator is a breathing trainer that creates gentle resistance on your exhale, slowing it down without you having to force it or count your breaths.

It can help with stress, tension, shallow breathing, or mental fatigue, and build your tolerance to CO₂. Five adjustable resistance levels let you start wherever your baseline is and build up from there.

Most people notice a sense of calm and better breathing awareness within the first few sessions. With consistent use, these benefits can grow into steadier breathing control, more resilience under stress, and more comfortable breathing in day-to-day life.

Slow, controlled breathing is linked to the activation of your parasympathetic nervous system, the state your body needs to rest and recover.

It's compact, requires no batteries, and is easy to carry wherever you go, at home, at work, or while traveling.

Get one today. Link in bio.