Breathwork Side Effects and Safety: What's Normal and Who Should Skip It

We have run Breathwork sessions since 2018: group classes, private sessions, corporate events, and retreats. Ryan has completed 7 Breathwork training programs and holds 4 certifications, and 55 students have enrolled in our facilitator training. Shelby is a registered nurse.

What Happens in Your Body During Breathwork

Respiratory Alkalosis

Breathe faster or deeper than your body needs and you exhale carbon dioxide (CO2) faster than you make it. CO2 regulates blood pH, so as it drops, pH rises above its normal range (roughly 7.35 to 7.45), a temporary state called respiratory alkalosis. Nerves and muscles get more excitable, so the hands and face tingle and feel pressure.

Tetany and Carpopedal Spasm

Tetany startles first-timers most. Muscle fibers fire on their own, usually in the hands, face, or feet, and the hands can cramp or lock. It is muscle tension, not a seizure. We hyperventilate on purpose in our sessions, with short breath holds, and tetany clears within minutes of slowing down. Panic makes it stronger, so we explain it first.

Lightheadedness and Visual Changes

CO2 widens the blood vessels in the brain. As it drops, they constrict (vasoconstriction) and brain blood flow dips, so some people feel spacey or see colors behind closed eyes. Fainting (syncope) is rarer, and people lying down come back quickly. The real risk is falling, so intense Breathwork is done lying on a mat.

Sympathetic Nervous System Activation

Active connected breathing raises heart rate and blood pressure and releases adrenaline. In healthy adults this passes on its own. It is also why heart conditions top the contraindications below.

Emotional Release

Crying or laughter that comes and goes is the most common response in our group sessions. Altered breathing changes brainwave activity and shifts the sympathetic and parasympathetic balance. See our trauma-informed Breathwork guide.

Normal vs. Concerning Breathwork Side Effects

What Happens	Why It Happens	Normal or Concerning?	What to Do
Tingling in hands, feet, or face	Respiratory alkalosis	Normal	Breathe more gently
Hands, face, or feet tensing up (tetany)	CO2 drop from fast breathing	Normal; resolves quickly	Slow your breathing
Lightheadedness or dizziness	Cerebral vasoconstriction	Normal while lying down	Breathe naturally
Seeing colors or lights behind closed eyes	Altered blood flow and alkalosis	Normal	No action needed
Emotional release (crying, shaking, laughter)	Somatic release	Normal and often the point	Let it move
Temporary fatigue after the session	CO2 rebalancing	Normal	Rest, hydrate, eat lightly
Brief fainting that resolves immediately	Reduced brain blood flow	Uncommon; not dangerous if lying down	Tell your facilitator; review your health history
Chest pain during or after	Not a normal breathwork mechanism	Concerning; stop immediately	Get a medical evaluation before more Breathwork
Dissociation that lasts past the session	Possible trauma activation	Concerning if prolonged	Grounding; consider trauma-specific support
Prolonged hyperventilation you cannot slow down	Panic response or technique issue	Concerning if unresponsive to verbal cues	Stop the technique; breathe into cupped hands

Lasting Side Effects for Regular Practitioners

Most people get none. The exception is people who do high-intensity hyperventilatory practice most days.

CO2 Tolerance and the Overbreathing Tendency

CO2 tolerance is how comfortable your nervous system is with higher carbon dioxide. Higher tolerance means slower breathing at rest and a later alkalosis threshold.

Daily intense circular Breathwork for months or years can lower that tolerance slightly, so you breathe faster or shallower between sessions. A few sessions a week will not do this. To offset it:

• Nasal breathing during workouts: Keeps CO2 higher and supports nitric oxide production on walks or easy runs.
• Box breathing (4-4-4-4): In, hold, out, hold, four counts each, for five minutes each morning.
• Slow exhale practices: In for four, out for six to eight, for ten minutes. The long exhale engages the parasympathetic nervous system.

How Surrender-Based Breathwork Differs

Holotropic Breathwork, rebirthing, and some somatic modalities push hard and treat catharsis and shaking as signs of depth. They help people, and we have trained in some of them, but we do not teach them. Ask which kind you are getting before you book a session or a facilitator training program.

Liquid Breathwork is surrender-based. We guide people to soften resistance to what is already present instead of driving CO2 as low as possible for as long as possible. People still tingle and feel spacious, but extreme tetany and long dissociation are rarer.

Breathwork Contraindications

Absolute Contraindications for Intense Breathwork

Skip intense circular Breathwork with any of these unless a doctor is supervising.

• Cardiovascular conditions: Heart attack within 6 months, cardiac arrhythmia, high blood pressure not controlled by medication, heart failure, or past stroke. Active Breathwork raises cardiac demand.
• Epilepsy or seizure disorders: EEG testing uses hyperventilation to provoke seizures, and it triggers seizures in most people with absence epilepsy, so hyperventilatory Breathwork carries real seizure risk. Practice only with physician clearance and medical supervision on site.
• Current pregnancy: In a study of women in labor, lower maternal CO2 from hyperventilation tracked with lower oxygen levels in the baby's umbilical blood. Gentle breathing with no breath holds and a slow exhale is generally fine with OB guidance.
• Active psychosis: Altered states can destabilize psychotic disorders, including in people who recently stopped antipsychotic medications.
• Untreated bipolar disorder in a manic phase: Intense Breathwork can trigger or intensify mania. With a bipolar diagnosis, consult your psychiatrist first.
• Glaucoma or retinal detachment: Breath holds that let CO2 build up can raise eye pressure, and so can bearing down while holding (the Valsalva maneuver).
• Recent major surgery: Within 3 months, especially abdominal, thoracic, or eye surgery. Intense breathing can disrupt healing.
• Severe uncontrolled asthma or COPD: Controlled hyperventilation can trigger bronchospasm or respiratory distress.
• Known aneurysm (brain or aortic): Blood pressure spikes during active Breathwork raise the risk of rupture.

Relative Contraindications

Tell your facilitator and start with gentle Breathwork.

• Well-controlled anxiety disorders, if you already see a therapist or psychiatrist
• Panic disorder
• Stable, well-managed bipolar disorder in a euthymic state
• Controlled asthma with an inhaler available at the session
• Trauma history without current active symptoms
• Raynaud's syndrome or peripheral vascular conditions (tingling and spasm can be stronger)
• Blood pressure or heart rate medications (check with your prescribing physician first)
• Psychiatric medications (ask how they interact with altered states)
• Age 65+ without a recent cardiovascular checkup
• A history of dissociation without reliable grounding skills
• Complete beginners (take your first breathwork class with an experienced facilitator, not alone at home)

Who Should Not Do Intense Breathwork

Intense means circular breathing that drives CO2 low, not slow relaxation techniques. Beyond the list above, skip it when heavily intoxicated or in active substance withdrawal.

Our community classes in the Phoenix metro area run small and gentle for first-timers.

Breathwork and Anxiety

For anxiety we use slow Breathwork with long exhales, which has good research behind it for heart rate variability and vagal tone.

High-intensity circular Breathwork feels a lot like a panic attack, so someone with panic disorder can read a normal response as danger. More in our Breathwork for anxiety guide.

Is Breathwork Dangerous?

Not for healthy adults who have shared their health history.

A slow diaphragmatic session and a long high-intensity circular one carry different risks. The real breathwork risks are undisclosed health conditions, the wrong technique for the person, pushing too hard, and practicing alone.

Questions to Ask a Facilitator Before Your First Session

1. "Do you ask about health conditions before each session?" The answer should be yes, every time.
2. "What happens if someone has an intense reaction?" Listen for a grounding protocol: cues to slow down and a check-in afterward. "Trust the process" alone is not an answer.
3. "What training do you hold, and how many hours?" Expect named programs and hour counts.
4. "Do you have experience with [your situation]?" Name it (anxiety, trauma, a heart concern). They should say yes or refer you out.
5. "What are your contraindications for this technique?" A trained facilitator can list them on the spot.
6. "What does the session look like from start to finish?" Intake, technique, music and pacing, and integration.
7. "Will I be lying down during the active breathing?" For connected or circular Breathwork, always.

What to Expect During a Session

First 5 minutes: You breathe in a circle, with no pause between inhale and exhale. Fingers and lips often tingle.

Minutes 5 to 15: Some people's hands cramp, and emotion can come up with no obvious cause.

Minutes 15 to 30: Sensations peak, then settle as CO2 levels out.

After: Sensations clear. Stay for integration, usually 10 to 20 minutes of quiet rest.

Frequently Asked Questions