The Science of Breathwork: Why Tetany Happens
Breathwork has surged in popularity as both a therapeutic and spiritual practice. From ancient yogic pranayama to modern holotropic sessions, controlled breathing can alter body chemistry and consciousness in powerful ways. One of the most striking experiences people report is tetany — involuntary muscle cramps, tingling in the hands and face, or spasms in the arms and legs. Though it can feel alarming, there’s a clear physiological explanation.
How Breathwork Changes Blood Chemistry
When you intentionally breathe faster and deeper than your body normally needs — a form of hyperventilation — you exhale large amounts of carbon dioxide (CO₂). Because CO₂ in our blood is acidic, exhaling too much of it tips the blood toward alkalinity, a state called respiratory alkalosis.
Normal breathing: CO₂ levels are balanced, blood pH stays near 7.4.
Hyperventilation: CO₂ levels drop (hypocapnia), blood pH rises (alkalosis).
This chemical shift has cascading effects on nerve and muscle function.
Calcium and Nerve Excitability
In the bloodstream, calcium exists in two forms: calcium bound to proteins and ionized (free) Ca+2 . It’s the ionized calcium that stabilizes sodium gated channels in nerve and muscle membranes. Those channels open when the membrane depolarizes to a threshold voltage causing the nerve to ‘fire’ or the muscle to contract. Extracellular calcium normally raises this threshold by binding to the outer portion of the sodium channel protein, making it less likely to open spontaneously.
However, when blood becomes more alkaline:
More calcium binds to proteins (especially albumin).
Less ionized calcium remains available.
The result: functional hypocalcemia (not a drop in total calcium, but in the usable fraction).
Why does this matter? Calcium normally keeps nerve sodium channels “quiet” by making them harder to open. With less free calcium, the threshold for firing drops. Nerves become trigger-happy, firing off action potentials with minimal provocation.
From Chemistry to Experience: Why Tetany Feels the Way It Does
This nerve hyperexcitability manifests as:
Tingling and numbness (paresthesias), especially around the lips, hands, and feet.
Carpopedal spasms — hands curling into claw-like positions.
Facial twitching or muscle cramps.
Occasionally, throat tightness or spasms.
In breathwork circles, these sensations can be reframed as part of the release process, though physiologically, they’re a direct outcome of alkalosis-induced hypocalcemia.
Is It Dangerous?
For healthy people, this state is usually temporary and harmless. Once normal breathing resumes, CO₂ levels rise, blood pH balances, and ionized calcium returns to baseline. The cramps and tingling fade within minutes.
Potential risks include:
Fainting from reduced blood flow to the brain. Low CO₂ causes cerebral vasoconstriction reducing blood flow and oxygen despite blood O₂ levels being high.
Arrhythmias in people with heart conditions. Related to the same Ca+2 and blood pH considerations.
Seizures in those predisposed.
Rarely, laryngospasm (airway spasm), which can be serious.
That’s why structured breathwork practices emphasize safe settings: lying down, guided facilitation, and medical screening for participants with health conditions.
Reducing Risks and Enhancing Benefits
Now that we know some of the physical risks and how they come about, what can we do to help manage those risks?
1. Set & Setting
Always lying down or comfortably seated — so if dizziness or fainting happens, no fall risk.
Supervision with a trained facilitator or a trusted sitter present. Solo hyperventilation practice isn’t advised.
Do breathwork in a safe space: auiet environment, away from water, heights, or sharp objects.
2. Pacing & Technique
Gradual build: Not every session has to be full-force hyperventilation. Start gently, explore different rhythms (e.g. coherent breathing, box breathing) before diving into cathartic breathwork.
Intervals: Alternate intense phases with grounding/rest phases. This prevents prolonged hypocapnia and helps integration.
Awareness cues: If tetany, dizziness, or distress gets overwhelming, slowing or pausing the breath restores balance quickly.
3. Screening & Contraindications
Certain conditions heighten the risks of reduced cerebral blood flow, arrhythmia, or seizure threshold shifts:
Cardiovascular disease or arrhythmias
Epilepsy or seizure disorders
Severe asthma or COPD
Pregnancy
If any of these apply for you, adapt with less intense breathing or avoid entirely.
4. Grounding & Recovery
Slow recovery breaths (gentle nose-breathing, extending the exhale) bring CO₂ back up and rebalance pH.
Body shaking, stretching, or humming can discharge leftover energy and stabilize the nervous system.
Hydration and reflection help integrate the experience.
5. Mindset & Integration
Expect the sensations: Knowing tingling, cramps, or dizziness are expected helps reduce fear.
Reframe tetany: Rather than danger, it can be seen as a sign of nervous system activation and release.
Aftercare: Journaling, quiet time, or group sharing helps anchor the insights rather than just chasing the high.
Takeaway
While tetany can be alarming or significant expererience, it isn’t mystical by itself. Hyperventilation lowers CO₂, alkalosis reduces ionized calcium, and nerves become overly excitable. The result is tingling, spasms, and sometimes intense body sensations.
Far from being random, these effects highlight how intimately breath, blood chemistry, and nerve function are linked. Understanding the mechanism can help practitioners approach breathwork with both curiosity and respect, using knowledge to enhance safety while still exploring its transformative potential.
