Tag: science

  • Tetany during Breathwork – or “The Breathwork Claw”


    Note: In this blog I’m only going to discuss tetany in the context of breathwork since people are often interested in why such a physical change occurs. I’m not going to touch on other medical reasons that can cause tetany in other ways.

    In the context of breathwork, tetany or “the breathwork claw” is a side effect that causes the fingers of the hand to typically close inwards into a lobster claw shape.

    What it typically looks like when you are doing breathwork is below.

    This is a temporary reaction by the body to what is going on at a chemical level in the body/blood.

    So, why does this happen?


    When we do Conscious Connected Breathwork, we are temporarily, deliberately changing the way we breathe, removing the pauses/gaps in our breath pattern. This usually means that we end up breathing out more gas than normal. Since the main “waste” gas we breathe out is Carbon Dioxide (CO2), then we expel more CO2 than normal. This loss of CO2 is more pronounced if we are breathing very fast or hard, especially when using too much force or effort on the out breath. CCB facilitators are very often heard saying things like “a soft outbreath”, or “let the out-breath fall out of your body”, “don’t push the out-breath”. Often this level of softness can be challenging since it requires us to “let go” of the out breath, and thus also let go a level of emotional control.


    If we breathe out more CO2 than our body is generating (CO2 is a biproduct of processing glucose), then this changes the pH level of our blood (pH is the scale of how acidic to alkaline a liquid is).

    Since CO2 is a kind of gas-version of acid (mixed with water it makes a weak acid called carbonic acid), then we are effectively removing acid from our system faster than we are adding it, thus we end up more alkaline.


    Our body is very keen on our blood staying at just the right pH level, not too acid and not too alkaline (typically at 7.4). The normal resting range is 7.35 to 7.45, but if you run a marathon you might get down to 7.1 and during breathwork you might get up to 7.6. Our bodies are able to adapt to these temporary shifts which are in fact stress-testing the system. [Note that the pH scale is from 1 (very acidic) to 14 (very alkaline) with 7 being perfectly neutral, so we see that the body prefers the blood to always be very slightly alkaline.]

    The body has a number of ways to affect the pH which work at varying speeds:

    1. The Chemical buffers – acts in milliseconds

    These are the bloods internal “shock absorbers”, normally used to remove small amounts of acid from the blood, like lactic acid from sprinting for the bus.

    These are limited in capacity and can easily be overwhelmed if you keep breathing off CO2.

    2. The Breathing Override – acts in seconds

    This could be an apnea, where the brain stops the breathing process completely (holding your breath) to retain CO2 and allow more of it to build up internally, increasing the CO2 level.

    3. The Protein-Calcium lock – seconds or minutes

    This is what generally causes tetany and what we will be mostly looking into.

    4. The Renal Clean-up – hours or days

    If the blood pH level remains away from the expected level, then eventually the kidneys start to adjust how much bicarbonate (anti-acid) they are pushing into the blood stream, the kidneys can either increase or decrease the level depending on what is going on over time but generally the body uses this to make the system less acidic. When a client does CCB then the kidneys might adjust their levels which is why it is always recommended to drink plenty of liquids afterwards, including the day after too.

    Looking at the Protein-Calcium lock in detail

    When the blood becomes more alkaline (less acid) then the body starts looking for “acid” to bring the pH back to a more neutral level.

    But before we look at this in detail, I realised that I wanted to really understand what “acid” meant. If you already know then you can skip the next section.

    The Chemistry behind Acidity

    In this case “acid” is effectively having lots of Hydrogen ions (H+) in the blood/plasma, which is mostly water, and water is probably not as simple as you might think.

    I always thought of water as just H2O. Everyone’s heard of that name and it sounds nice and simple. But under the surface, water is constantly shifting between H2O and a combination of H3O+ and OH (which when recombined make two lots of H2O). This is called auto-ionization. Here we can think of the H3O+ as H2O plus an H+ (acid) and the OH as H2O with a missing H+ (alkaline).

    H2O + H2O <=> H3O+ + OH

    (which is equivalent to)

    H+ + H2O + OH


    When we have pH neutral water then the number of H+ and OH floating around, changing back and forth are basically equal. This is why water is such a great base for acids, because it already has the ability to include H+ ions.


    If we add CO2 (carbon dioxide) to water in the body, an enzyme in the blood helps them combine into a very unstable form of acid called Carbonic Acid (H2CO3), and this rapidly breaks down into H+ and HCO3. Thus we end up with extra H+ in the water (higher ion density), and some dissolved Bicarbonate ions (the HCO3).


    If we remove CO2 by breathing out, then basically the opposite happens. An existing HCO3 grabs a spare H+ and turns back into H2O and CO2, and the CO2 is then expelled from the system.


    The interesting thing in the body though, is that CO2 is constantly being produced as a waste product as we process glucose into energy. There is a constant addition of acid into the blood. The exit point for this CO2 is breathing out. If we stop breathing out then the CO2 / acid / H+ in the blood gradually rises. In a normal resting state the amount of CO2 the body produces should match the amount of CO2 we are breathing out. This then controls the number of H+ in our blood.


    A Hydrogen ion (H+) is actually a proton that really wants an electron to be orbiting it, but hasn’t got that electron. Each H+ is like a window frame that needs glass in it, much more strongly than other items containing glass need their glass, such that the window frame will take glass from other structures that it gets close to, breaking the other structures to get their glass.


    This is how acid “burns” through substances like metal. For example, if we take a neutral metal like Aluminium and add Hydrochloric Acid, then each H+ in the acid has a stronger “need” for the electrons (the “glass”) in the Aluminium than the metal itself – thus you get a fizzing effect as the H+ steal electrons to turn into a stable H2 hydrogen gas (the hydrogen has regained its natural number of electrons) and the Aluminium ends up as a water soluble version of itself (Al3+), which then dissolves into the water part of the acid. Note that you cannot really have “pure” acid, just very acidic water (or other base) which contains a lot of H+ compared to normal. Also, this kind of aggressive acidic behavior is very much not happening in our blood, but it demonstrates the chemistry.


    So, having overly acidic blood (lots of wandering H+) is not something your body is happy about since the H+ tends to go around changing and breaking things. Not what we want inside our body, even if it’s only happening a little.

    To manage this situation the body has an active defense running all the time to soak up spare H+ ions. This is a baseline level of bicarbonate the body keeps in the blood, which as we’ve seen before is HCO3. This will bond to spare H+ to keep the number of H+ floating around under control. Ideally there is a ratio of something like 20:1 of HCO3 : H+ in the blood which produces a pH of roughly 7.4. We need more HCO3 since the H+ is aggressively looking for something to bond to, so having plenty of spare capacity saves the H+ finding another source the body was not expecting.

    Ideally there is a ratio of something like 1:20 of Acid (CO2) : Alkali (HCO3) in the blood which produces a pH of roughly 7.4, slightly alkaline. The body keeps 20x more HCO3 since the acid (H+ ions) is aggressively looking for something to bond to, so having plenty of spare capacity saves the H+ finding another source the body was not expecting.

    Interestingly, the acid strength (concentration of H+ ions) that this ratio produces can be rapidly altered when CO2 is added or removed. If we look at the result of adding a few extra CO2 (thus H+ and HCO3 ions) we see that the acid concentration can shift very fast.

    ActionDissolved CO2 : BicarbonateAcid ConcentrationNotes
    Baseline1 : 200.05Normal concentration
    Add 45 : 240.2Adding 4 produces a 4x change in concentration, a 400% increase
    Add 1011 : 300.36Adding 10 produces a 7x change in concentration, 700% increase
    Remove 0.50.5 : 19.50.025A change down by 50%

    This shows how quickly we can impact the concentration of H+ ions in the blood with small changes to the amount of CO2 in the system due to the baseline ratio difference.

    When we connect the breath, continually breathing out CO2, the blood quickly ends up with too few H+ in it, which the body (and chemistry) is also trying to avoid, which brings us back to…

    Back to the Protein-Calcium lock

    When there is a lack of H+ in the blood due to breathing out lots of CO2 then this affects a protein/compound in the blood called Albumin. This is a complex molecule which normally has lots of negative slots in it that H+ likes to bond to (negative and positive bind together like magnets).

    However, when the blood needs more H+ since there is not enough, then the Albumin gives up some of its own H+ into the blood to balance the pH. However, this leaves a negative space in the Albumin, acting kind of like a specialized chemical vacuum that attracts positively charged ions. Another type of ion that is floating around in our system are Calcium ions. If these get the chance they will bond into the negative spaces in the Albumin instead of being where they are supposed to be.


    For completeness, if the blood is too acidic (you are holding your breath or your breath is very shallow) then we end up with too many Calcium ions being released into the blood, see later for the effects this has.

    The cause of tetany

    Nerves fire when Sodium (Na+) enters a nerve trigger gate. A gate can be opened by a “signal” like physical touch for a sensory nerve, or chemically for other nerves. When the gate is opened then Sodium can enter and fire the nerve. The thing that is “guarding” this gate are Calcium ions (Ca2+) which increase the electrical threshold required for the gate to accept triggering Sodium ions. If we remove the Calcium ions then much lower electrical signals (the body is full of small signals) will trigger nerves to fire as the Calcium ions are no longer guarding the gate.

    This means that nerves are firing more easily than normal since the sensitivity of the nerves is not being dampened by the Calcium ions that are now bound to the Albumin instead of doing their normal job.

    As all the nerves of the hand become more sensitive, this initially causes tingling sensations, and as the sensitivity increases can eventually cause the muscles to twitch or fire/tense up. Since most peoples muscles for gripping things are stronger than the ones for opening your hand, if all the muscles in the hand become tense, then the hand will close up and you will not be able to move it until the Calcium ions are released back into the blood to continue their normal role.

    When we stop exhaling the CO2 so fast, the CO2 and thus H+ builds up to normal levels in the blood very quickly and the Calcium ions are then released back into the blood and everything goes back to normal – the nerves stop firing so easily and the muscles can relax.

    Why is shifting to a more alkaline state a useful cleanout?

    Everything in the body is always trying to find balance, there is no ideal, just an equilibrium. When there is a lot of H+ (acid) in the blood, then most/all of the Calcium ions are kicked off the Albumin into the blood, and act as surplus “guards” for the nerves. Thus the nerves become sluggish to fire and the body and sensations feel slow and dull.

    When we are living in chronic stress, often holding our breath due to situations or tension, the CO2 builds and so does the acid in our blood.

    Acidic blood => High Free Calcium => Numb Nerves

    Thus stress is not only affecting your mood, it is physically affecting your ability to feel by dampening your nerves.

    During breathwork we deliberately reduce the H+ in the blood and reduce the number of Calcium ions guarding the nerves.

    Tetany is an indication that we are pushing too hard, we have stepped slightly over our own current window of tolerance to blowing out CO2. In CCB we don’t need to try so hard, even with a small shift in blood pH (minor tingling) we are getting all the benefits of waking up the nerves.

    This increased nerve response helps the brain to recalibrate these nerves, or possibly to actually notice for the first time in a while that these nerves are still present and active – it wakes us up.

    We literally regain the ability to fully feel our bodies again.

    And once we can feel it, we can bring awareness, change and more life into our bodies.

    Wrapping up

    Understanding the body chemistry of “The Claw” highlights another aspect of how Conscious Connected Breathwork can move us from a “Grey” life into a more vibrant one, even on a purely physical level.

    Whether you’ve spent decades overclocking your mind while your body suffered in silence, or have reached a point where it feels like no amount of talking can shift you out of feeling numb, maybe it is time to work directly with your body using the power of your breath.

    If you are interested to experience this breathwork yourself, I am offering one-to-one sessions in North London, EN4.

    Maybe we can breathe together soon.



    And finally, how can we have a blog about “The Claw” without referencing this Jim Carey movie (final scene…)

    Link: YouTube

  • The brain science behind Conscious Connected Breathwork in 2025

    There are many types of breathwork in existence. The style that I work with is Conscious Connected Breathwork. This style is known for working with the emotions in the body, often called “therapy without talking”. But how can something as simple as breathing have such profoundly healing results? The researchers are interested in finding out too…

    I recently found a study which looks into what is going on inside the brain and body that allows this breathwork to make changes in emotions held for years in the body [“Neurobiological substrates of altered states of consciousness induced by high ventilation breathwork accompanied by music,” published by Kartar et al. (Colasanti Lab, Brighton & Sussex Medical School) in PLOS ONE (August 2025)” link].

    It is fascinating stuff, but rather dense. So here is my attempt at an explanation of what they found.

    What did they do?

    This was a study on High Ventilation Breathwork (HVB *). This type of breathing was done by the participants for a period of time, gradually increasing their breathing rate. This connected breath style changes the mix of oxygen and CO2 in the blood.

    There were 27 participants and the results I focused on are the in-person lab results.

    * HVB in this case seems to be a generic term for the same breath style used in Conscious Connected Breathwork (CCB). In the study they included music, but no guidance, affirmations or touch so the effectiveness of the breathwork would have been lessened compared with CCB.

    What did they measure?

    The researchers measured blood flow in different parts of the brain, the flow rate and oxygen usage. This allows them to see which parts of the brain were active and which were passive during the different phases of the breathwork (resting, starting breathwork, fully active breathwork).

    They also measured a number of subjective experiences, from the standard 5D-ASC measures of experience. I’ll highlight two here.

    Oceanic Boundlessness (this increased). This is a shorthand for “spiritual experience, insightfulness, blissful state, positively experienced depersonalization, and the experience of unity”.

    The most interesting feature of Oceanic Boundlessness is that it is “reportedly the most accurate predictor of antidepressent actions of psychedelic substances”.

    It is quite amazing to me that simply by changing how we breathe can take us into a state otherwise typically requiring psychedelics.

    Dread of Ego Dissolution (this stayed flat). This is measuring the concern of losing control, the anxiety around what is going on. This is your prefrontal cortex fighting to stay in charge of the situation. In my experience of talking to people, this fear of “having a bad trip” or being “out of control” seems to be a major concern with psychedelic experiences.


    You can see that in all settings the DED stays low.

    The other reassuring thing about using connected breathwork to shift your mental state is that you can always just stop, breathe normally, and your physiological state reverts to normal within a couple of minutes at most, but the integration and healing from the session stays with you.

    What happens in the brain when we do CCB?

    When you breathe in a circular* fashion what happens is probably not what you expect.

    * Circular means no pauses after inhale or exhale. If you have a cat or a dog, watch them breathe when they are resting. This continuous circular pattern is how most animals breathe, but not how humans normally breathe.

    When doing CCB you are exhaling CO2 faster than your body can produce it. There is a whole other discussion around the role of CO2, but for now we will focus on the fact that CO2 is used in the brain as a vasodilator – it keeps blood vessels wide – so a reduction of CO2 in the system means reducedblood flow to the brain (7 – 19% reduction in Cerebral Blood Flow in general).

    At this point the body starts to prioritize which bits of the brain to keep fully online and which can slow down and take a back seat.

    The body always chooses safety over everything else. This is always a fundamental aim of our nervous system (even when it doesn’t feel like it to us).

    This figure from the study shows two areas of the brain lit up, while the rest of the brain becomes deactivated.

    With an R2 value of 0.784 the study shows a correlation of ~80%, where the experience of Oceanic Boundlessness is directly explained by the changes in blood flow.

    Zooming in shows amygdala and hippocampus active while the rest of the brain is passive:

    The body is prioritizing threat detection

    • the emotional alarm system (the Amygdala).
    • the memory indexing system (the Hippocampus), to ensure the emotional alarm system can recognise threats from our history.

    and deprioritizes ego, control, planning and tracking

    • the gatekeeper (the Prefrontal Cortex), which is always trying to keep everything “safe” and under control, it’s like the supervisor or manager.
    • the here-and-now tracker (the Posterior Insula), which is tracking your body sensations, how your body currently feels and where it is in the world.

    In a way, the brain moves from “standard mode” into “critical task mode”.

    Note that while the rest of the brain is quiet, the amygdala and hippocampus are running hotter than normal, they are not just business-as-usual.

    While the physical changes in the brain can be seen quickly when circular breathing starts, the emotional and thought-process experiences change in the breather slowly and gradually through the session.

    What experience does this result in?

    As the emotional alarm system and deep memory processing is given priority, the control and “ego” is given less.

    Now we move into interpretation of what could be happening based off the brain activity scans and my knowledge and experience of CCB.

    With the ego dialed back, the gatekeeper is not as active in interpreting, supressing and controlling feelings. We are not as worried about appearing to be in control all the time so we can allow feelings to express.

    With the here-and-now monitoring system turned right down, the normal stream of information about the body is still arriving, but our interpretation and filtering of that information is radically reduced. We stop labelling or even suppressing sensations from our body in our familiar way. This raw data can then be felt by the rest of the brain in full and without interference.

    Our memory system and emotional alarm system gradually get to run the show unencumbered by the gatekeeper.

    When working with in-person Conscious Connected Breathwork, the stimuli coming in are:

    • raw physical feelings from the body while breathing, possibly from old injuries or simply felt tension
    • touch, intensifying the physical feelings from the body, activating known acupressure points in the body where tension is often stored
    • music, often strongly linked to emotions and memories
    • affirmations, often triggering more memories or limiting beliefs

    When these stimuli bring up emotions, the ego gatekeeper is no longer actively trying to suppress some feelings, or come up with explanations and stories around them to explain them away, dampen them or stop them. The stored charge is released (homeostatic reset), the open loop can be closed.

    The brain and body get to feel the unfiltered sensations of the emotion and allow the feeling to run to completion.

    When the active part of the breathwork ends and breathing returns to normal, the ego gatekeeper and here-and-now monitor come back online and integrate the newfound felt experience of the body, now without the charge/tension that has just been released. As part of the integration the gatekeeper can drop any story it was running to suppress the old feeling since the story is no longer required.

    Why don’t other animals need breathwork?

    Why are the wild animals that live in semi-permanent danger not requiring breathwork sessions to remove their stress?

    Dr. Peter Levine, creator of Somatic Experiencing (SE) is one of the leading experts in trauma with over 50 years of experience in the subject. He often describes how trauma stays in the body until it can be “shaken off”.

    Here (YouTube link) Dr. Levine says

    “… that energy … gets shaken off. And then we restore to our nervous system balance. Again, it’s innate, but people, humans, have fought against that, and then it just accumulates.”

    Here you can see a polar bear being chased, sedated, then shaking off the stress of the experience (link)

    There are other examples where “caught” impalas or zebras manage to jump up from playing dead, run to escape, and then after escaping find a safe place to lay down and shake uncontrollably for a few minutes. This shaking dissipates the survival energy that remained in the body from the massive hormone dump, allowing any excess energy to be released from the system. Then they get up and carry on their life, appearing to be stress free despite walking so close to death.

    Note, the zebra does control this urge to shake for long enough to escape the situation. It too can suppress the shaking response when it needs to but the zebra doesn’t suppress it for longer than required.

    Why do humans fight against this natural physical method to release stress and why are they so good at it?

    My intuition is that it is due to our strong social conditioning and the relatively large size of our prefrontal cortex. Throughout early life we learn that we must look and be “normal” to fit in and be safe in the group, and shaking uncontrollably just doesn’t fit into that very well, at least not previously. In my cultural upbringing there was a definite underlying message that I needed to Keep Calm and Carry On, just like the coffee mugs say. For me this story became very powerful, I was self monitoring constantly. Even in private this internal messaging was active for me (and probably many others), restricting my ability to ever truly let go. The relatively large prefrontal cortex (ego gatekeeper) means we can exert control over the rest of the system for a long time (possibly years), keeping us out of balance, which often comes at a price. For me the price was a reduction of my emotional range in order to keep me functional, making my world into shades of grey and leading to functional depression.

    Using breathwork to turn down this egoic gatekeeper part of the brain in a suitably safe environment, the body and nervous system can then do what it has wanted to since the original time of stress without judgment. This doesn’t always have to result in shaking or movement, but the bodies wisdom can now do what is required to complete the stuck cycle.

    Finally the stored stress energy can be expressed and released.

    How it feels after a breathe

    I find that the experience of this process is different each time I breathe, and many others report the same. The key thing I feel is that after a breathe something has lifted.I feel like a weight has been removed from my life.

    Possibly a fully repressed feeling has been felt for the first time in years, possibly since early childhood. Felt and released.

    Sometimes the release can be gradual and take multiple sessions to work through, sometimes great change can happen in a single session.

    Each time I breathe, I feel a bit better than before.

    Wrapping up

    Ongoing research is bringing new understanding to how Conscious Connected Breathwork is such a powerful healing tool.

    I found this research paper very interesting. I am one of those people that like to know how things work, although not knowing doesn’t stop me using methods that bring me good results. I’m a pragmatist at heart.

    Note that CCB also has lots of purely physical health benefits which I’ve not mentioned here.

    I am interested to hear your comments. Is this news to you or does it fit into your existing mental model?

    If you are interested to experience this breathwork yourself, I am offering one-to-one sessions in North London.

    Possibly we can breathe together soon.