Functional Breathing and Your ADHD Nervous System

Low Tide Blog · ADHD & Functional Breathing

Why Your ADHD Brain Can't Calm Down (And What Your Breathing Has to Do With It)

Functional breathing, nervous system regulation, and the thing nobody in Ireland is talking about.

14 April 2026 · 12 minute read

You have tried the meditation apps. You have sat through guided body scans that felt more like torture than therapy. You have been told to "just breathe" by well-meaning people who clearly have no idea what it is like inside your head.

Here is the thing: they were half right. Breathing is the answer. Just not the way they think.

If you have ADHD, there is a good chance your nervous system is running on a setting that was never designed for everyday life. And there is growing evidence that the way you physically breathe, right now, while you are reading this, is both a symptom of that dysregulation and a way back from it. This is the conversation almost nobody in Ireland is having. Let's have it.

Your nervous system isn't broken. It's stuck.

Your autonomic nervous system has two main modes. The sympathetic branch (fight or flight) revs you up. The parasympathetic branch (rest and digest) brings you back down. In a well-regulated system, these two work together like a seesaw, tipping back and forth throughout the day as needed.

With ADHD, that seesaw does not move the way it should. It lurches. You go from zero to overwhelmed in seconds. Or you are stuck in a fog you cannot shake until suddenly you are wired at 2am. This is not a personality flaw. It is physiology.

A 2020 systematic review by Bellato, Arora, Hollis & Groom at the University of Nottingham, published in Neuroscience & Biobehavioral Reviews, looked at 55 studies examining autonomic nervous system function in people with ADHD. They found that ADHD is associated with atypical autonomic regulation, with many studies pointing toward hypo-arousal at rest. In plain terms, the system is under-powered at baseline, not over-powered. This is part of why stimulant medication works: it raises arousal to a functional level.

Here is the twist. That baseline under-arousal means the ADHD brain is constantly compensating. Seeking stimulation, struggling to engage, running on fumes. Layer chronic stress, poor sleep, and anxiety on top (and clinical estimates put the rate of co-occurring anxiety disorders in adults with ADHD at around 30 to 50%), and you get a nervous system that toggles between collapsed and wired with very little time in the regulated middle ground.

Not simply "too calm" or "too activated," but a system that cannot find its footing.

The research backs this up. Bellato's review noted that the findings across studies were often inconsistent, which suggests the problem is not a fixed state in one direction. It is a regulation problem. The system struggles to match its response to the demands of the moment. So when someone tells you to relax and you genuinely cannot, it is not because you are not trying hard enough. Your nervous system is doing its best with a gearbox that does not shift smoothly. More on the connection between ADHD and ADHD burnout elsewhere on the blog.

Now let's talk about how you're breathing

Here is where it gets interesting, and a bit uncomfortable. Most people with chronically dysregulated nervous systems do not breathe well. And most people who do not breathe well have chronically dysregulated nervous systems. These two things feed each other in a loop that almost nobody is addressing directly.

What does "not breathing well" look like?

• Breathing through your mouth, especially at night
• Breathing into your upper chest rather than your diaphragm
• Taking big, visible breaths (sighing, yawning, gulping air)
• Breathing faster than you need to, even at rest
• Feeling like you can never get a satisfying deep breath

If you ticked two or more, you are not alone. And if you have ADHD, there is a particular reason this matters.

Dysfunctional breathing patterns reduce carbon dioxide (CO2) tolerance. Before you switch off because that sounds like a chemistry lecture: CO2 is not just a waste gas. It is what allows your red blood cells to release oxygen to your tissues and brain. This is the Bohr effect, basic textbook physiology. When you chronically over-breathe, your CO2 levels drop. When CO2 drops, oxygen delivery to your brain becomes less efficient. For the ADHD brain, which already struggles to maintain optimal arousal, that is a problem. It means the brain has to work harder just to keep up, feeding the compensatory stress responses that leave you feeling simultaneously exhausted and on edge. More detail on this in why you cannot take a deep breath.

The Buteyko connection (and why it matters for ADHD)

The Buteyko method is a breathing retraining approach developed by Soviet physiologist Dr Konstantin Buteyko in the 1950s. Originally designed for asthma patients, it has since been acknowledged in UK and Scottish clinical guidelines on asthma management as a complementary approach that may help patients control symptoms. (The full history and evidence base is covered in more depth elsewhere.)

What caught my attention as someone with ADHD who is also trained in this method: Buteyko's core principles map directly onto the problems ADHD creates in the body. The three pillars:

What the research says (and what it doesn't)

I need to be straight with you, because intellectual honesty matters more than a sales pitch. The direct research connecting Buteyko specifically to ADHD outcomes is limited. Most Buteyko studies have focused on asthma, where the evidence is moderate and growing. A 2020 Cochrane review found that breathing exercises (including Buteyko) may have some positive impact on quality of life and hyperventilation symptoms for asthma, though with moderate to low certainty.

What is well established:

Nasal breathing improves sleep quality. Sleep disruption is one of the most under-treated drivers of ADHD symptom severity. Case reports and clinical observations have shown that correcting sleep-disordered breathing (often related to chronic mouth breathing) reduces ADHD symptom load in some children.

Slow, reduced-volume breathing activates the parasympathetic nervous system. Basic autonomic physiology, supported by multiple studies including Ma et al. (2017) in Frontiers in Psychology, which found that diaphragmatic breathing training improved sustained attention and reduced cortisol levels in healthy adults over eight weeks.

Breathwork reduces anxiety symptoms. Banushi et al. (2023) in Brain Sciences conducted a scoping review of sixteen clinical studies and found a range of breathwork interventions yielded significant improvements in anxiety symptoms in patients with DSM-5 diagnosed anxiety disorders. The review noted contradictory findings on the specific role of hyperventilation, but the overall pattern supported breathwork as a clinically useful intervention. Given the 30 to 50% ADHD-anxiety overlap in adults, this is clinically relevant.

Breathing retraining improves quality of life as an adjunct to standard treatment. The BREATHE trial (Bruton, Lee, Yardley et al., 2018, published in The Lancet Respiratory Medicine) was the largest physiotherapy breathing retraining trial for asthma ever conducted. It found that self-guided breathing retraining improved quality of life and reduced healthcare costs for adults with asthma whose condition remained uncontrolled despite medication.

The honest picture: there is no randomised controlled trial yet that says "Buteyko breathing reduces ADHD symptoms by X%." What exists is a strong mechanistic chain (autonomic dysregulation in ADHD, CO2 tolerance as a lever for parasympathetic activation, nasal breathing as a gateway to better sleep), solid evidence for each individual link, and a growing body of clinical observation. Not proof. Not yet. But a reasonable hypothesis worth testing in your own body.

What this actually looks like in practice

If you have read this far (well done, ADHD brain, well done), you probably want to know what to actually do. A blog post cannot replace working with someone trained in breathing retraining. But here is a starting point.

Three things you can do today

Why this matters for ADHD specifically

I want to be clear about what I am not saying. I am not saying breathing exercises will cure your ADHD. ADHD is a neurodevelopmental condition with genetic, structural, and neurochemical dimensions. It is real, it is lifelong, and for many people medication is an important part of managing it.

What I am saying is that breathing is the most direct and accessible bridge between your conscious mind and your autonomic nervous system. It is the one bodily function where voluntary control and automatic regulation meet. That makes it the single most practical lever you have for nervous system regulation.

For ADHD brains, nervous system regulation is not a luxury. It is the foundation everything else sits on.

Your focus, your emotional bandwidth, your ability to sleep, your capacity to tolerate frustration without going nuclear: all of these depend on a nervous system that can move between activation and recovery without getting stuck. Functional breathing will not replace your medication, your therapy, or your routines. But it might be the missing layer underneath all of them. The thing that makes the other things work better. More on ADHD and emotional regulation in emotional resilience for ADHD and on breathwork and mindfulness for neurodivergent minds.

Cian O'Driscoll writes about functional breathing, nervous system regulation, and ADHD at Low Tide Calm. He has ADHD, is trained in the Buteyko method, is a certified mindfulness teacher (Mindfulness Now UK), and a complementary therapist. He works one-to-one with clients in Wicklow and online. Nothing in this post is medical advice and breathing retraining is not a substitute for ADHD clinical care, medication, or therapy. If you have respiratory conditions (asthma, COPD, sleep apnoea), check with a GP before starting structured breathing practices.

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Peer-reviewed research cited

Bellato, A., Arora, I., Hollis, C. & Groom, M.J. (2020). Is autonomic nervous system function atypical in attention deficit hyperactivity disorder (ADHD)? A systematic review of the evidence. Neuroscience & Biobehavioral Reviews, 108, 182-206. View on PubMed.

Banushi, B., Brendle, M., Ragnhildstveit, A., Murphy, T., Moore, C., Egberts, J. & Robison, R. (2023). Breathwork Interventions for Adults with Clinically Diagnosed Anxiety Disorders: A Scoping Review. Brain Sciences, 13(2), 256. View on MDPI.

Bruton, A., Lee, A., Yardley, L., Raftery, J., Arden-Close, E., Kirby, S., Zhu, S. et al. (2018). Physiotherapy breathing retraining for asthma: a randomised controlled trial (BREATHE trial). The Lancet Respiratory Medicine, 6(1), 19-28. View on PubMed.

Ma, X., Yue, Z.Q., Gong, Z.Q., Zhang, H., Duan, N.Y., Shi, Y.T., Wei, G.X. & Li, Y.F. (2017). The Effect of Diaphragmatic Breathing on Attention, Negative Affect and Stress in Healthy Adults. Frontiers in Psychology, 8, 874.

Cowie, R.L., Conley, D.P., Underwood, M.F. & Reader, P.G. (2008). A Randomised Controlled Trial of the Buteyko Technique as an Adjunct to Conventional Management of Asthma. Respiratory Medicine, 102(5), 726-732.

Clinical guidance and further reading

UK and Scottish clinical guidelines on the management of asthma (BTS/SIGN and NICE joint guidelines). These acknowledge breathing exercises, including Buteyko-style techniques, as a complementary approach. sign.ac.uk.

McKeown, P. (2021). The Breathing Cure. OxyAt Books. Chapter on ADHD and sleep-disordered breathing. Patrick McKeown is the founder of Buteyko Clinic International, based in Ireland.