What Is Hyperbaric Oxygen Therapy?
A clear look at the mechanism, the real evidence behind it, and how the mild 1.3 ATA wellness dose used at My BioHealth differs from clinical hyperbaric medicine.
- Mild HBOT (1.3 ATA) is a different category from clinical hyperbaric medicine (2.0+ ATA) — different evidence, different regulatory context, not a lesser version of the same thing.
- A systematic review examined mild hyperbaric exposure in people with persistent postconcussion symptoms, including protocols using 1.3 ATA. That is a diagnosed clinical population, so it is not direct evidence for a wellness service.
- The mechanism is real physics: increased pressure lets more oxygen dissolve directly into blood plasma, not just red blood cells.
- It's understood as a course of sessions, not a single visit — the evidence base reflects that, and so does how we structure our own programs.
Introduction
Hyperbaric Oxygen Therapy, HBOT, has moved from a niche medical treatment into mainstream wellness conversation over the past few years. But the term covers a genuinely wide range, from high-pressure clinical treatment for conditions like carbon monoxide poisoning, through to the mild, wellness-focused sessions offered at clinics like ours. This article explains what HBOT actually is, what the evidence does and doesn't show, and where the mild 1.3 ATA approach fits into that picture.
What is it?
HBOT involves breathing a higher concentration of oxygen while inside a pressurised chamber. The increased pressure allows your lungs to absorb meaningfully more oxygen than they would under normal atmospheric conditions, which is then carried through your bloodstream to tissue throughout the body. Chambers are measured in ATA, atmospheres absolute, a unit describing how many times greater the pressure is than standard sea-level atmospheric pressure. Clinical hyperbaric medicine, used in hospitals for conditions like non-healing wounds or serious carbon monoxide poisoning, typically runs at pressures of 2.0 ATA or higher, under strict medical supervision. Mild hyperbaric therapy, the category our chamber falls into, runs at 1.3 ATA, roughly equivalent to the pressure change of diving about ten feet underwater.
The basic physics, in plain terms
Under normal atmospheric pressure at sea level, your blood carries oxygen almost entirely bound to haemoglobin in red blood cells, with only a small amount dissolved directly in the plasma itself. Increasing the surrounding pressure changes this balance. As pressure rises, more oxygen physically dissolves into the blood plasma, independent of haemoglobin. This matters because plasma-dissolved oxygen can reach tissue through pathways that red-blood-cell-bound oxygen sometimes can't, particularly in areas with reduced blood flow. This is the basic physical principle underlying every form of hyperbaric therapy, from severe clinical applications through to mild wellness sessions, they all rely on the same underlying gas law, just applied at very different pressures and for very different purposes.
Why it matters
The distinction between mild and clinical HBOT matters because they represent genuinely different categories of use, with different evidence bases and different regulatory contexts. Conflating the two, treating a wellness session as equivalent to hospital-grade hyperbaric medicine, would overstate what a mild session can offer. At the same time, mild HBOT has its own, separate and growing body of research, distinct from the clinical literature, that's worth understanding on its own terms, which is exactly what the rest of this article sets out to do.
How a session actually works
A typical mild HBOT session involves lying or sitting comfortably inside the chamber for 30, 60 or 90 minutes, while the internal pressure gradually increases to 1.3 ATA. Most people describe the sensation as similar to the ear pressure change experienced during a flight's descent, generally comfortable, occasionally requiring a small equalisation technique like swallowing or yawning. Because our chamber seats two people, sessions can be shared with a partner, training buddy or family member. Many clients read, listen to music or simply rest during a session. There's no special preparation beyond avoiding a heavy meal beforehand and wearing comfortable cotton clothing, and no recovery period is usually required afterwards, so most people return to normal activity straight away. Individual responses can vary.
Current evidence
It's worth being specific here about what type of evidence exists, since not all research carries equal weight.
Clinical evidence: A systematic review analysing 11 studies of HBOT for persistent postconcussion syndrome, organised by oxygen and pressure dose, found symptom improvements recorded at 30 sessions using mild 1.3 ATA air specifically, the same pressure and gas mix used in wellness chambers like ours. This is a genuinely relevant, dose-specific finding, though it sits within a broader review that also examined other pressures and outcomes, some more positive than others. The review's own methodology graded studies for quality and bias, which is exactly the kind of rigour that separates a systematic review from a single anecdotal report.
The exact dose where a systematic review recorded genuine symptom improvement, using the same mild 1.3 ATA pressure our chamber runs at, not a higher clinical dose.
Emerging evidence: A 2025 case study published in Frontiers in Immunology documented a single patient who underwent 40 sessions of mild HBOT at 1.3 ATA over 10 weeks for chronic inflammatory response syndrome, with all 22 of her reported symptoms resolving and measurable reductions in specific inflammatory blood markers. This is a real, published finding, but it's a single-patient case study, the weakest tier of clinical evidence, and shouldn't be read as proof that similar results are typical or guaranteed. Case studies are valuable for generating hypotheses and pointing toward areas worth larger study, but they cannot, on their own, establish that a treatment reliably works for a given condition.
Theoretical mechanism: Research on mild hyperbaric sessions has also explored their influence on Nrf2 pathways, a cellular system understood to govern the body's own antioxidant enzyme production. This remains a mechanism under active study rather than a settled clinical outcome, it helps explain a plausible "why," not a proven "what happens to you." Similarly, increased tissue oxygenation is understood to support the energy-producing processes inside cells, though the practical, measurable effect of this in a wellness context, rather than a laboratory setting, is still an area of ongoing research rather than settled fact.
How mild HBOT compares to clinical hyperbaric medicine
It's worth being direct about this distinction, since the word "hyperbaric" alone can create a misleading impression. Clinical hyperbaric medicine is a recognised medical treatment for a specific, relatively short list of conditions, including decompression sickness, severe carbon monoxide poisoning and certain non-healing wounds. It's delivered in hospital settings, under direct medical supervision, typically at pressures of 2.0 ATA or considerably higher, sometimes using 100% oxygen rather than regular air. Mild HBOT, by contrast, is a wellness category. It runs at a lower pressure, commonly uses ambient air with mild oxygen enrichment rather than pure oxygen, and isn't positioned as a treatment for any diagnosed medical condition. The research bases for the two categories are largely separate, and it would be inaccurate, and against the standards we hold ourselves to, to imply that evidence for one automatically applies to the other.
Common misconceptions
A few misunderstandings come up often enough to be worth addressing directly. First, mild HBOT is not the same intensity as what's shown in medical dramas or used for severe injuries, those are entirely different pressure ranges and clinical contexts. Second, a single session isn't likely to produce a dramatic, noticeable change, the evidence base, such as it is, generally involves a course of multiple sessions over weeks, not a one-off visit. Third, "more pressure" doesn't straightforwardly mean "more benefit", higher pressure hyperbaric therapy carries its own risk profile and is reserved for specific clinical situations for good reason, not simply offered as a stronger version of the same wellness experience.
Clinical considerations
Mild HBOT isn't right for everyone. Contraindications can include a current chest infection or blocked sinuses, a history of collapsed lung, and pregnancy. This is exactly why a proper screening consultation happens before your first session at our clinic, not treated as a formality. If you have a significant medical history, speak with your GP before beginning any HBOT program, wellness-focused or otherwise.
Who may benefit
Based on the available evidence and typical clinical use, mild HBOT is commonly considered by people managing persistent fatigue, those recovering from intense training loads, and people interested in general cellular health and healthy ageing support. It's genuinely not a guaranteed fix for any specific condition, and individual responses vary considerably.
Common questions
No. Clinical hyperbaric medicine runs at higher pressures under medical supervision for specific diagnosed conditions. Mild HBOT at 1.3 ATA is a distinct, lower-intensity wellness category with its own separate research base.
Both exist. Systematic reviews of multiple studies represent stronger evidence, while individual case studies represent real but early, less generalisable findings. We think it matters to be clear about which is which, rather than presenting all research as equally settled.
Yes, full references are listed below, and our links directly to the source studies.
1.3 ATA sits within the wellness category, using regular air rather than pure oxygen, without needing the medical supervision and safety infrastructure that higher pressures require. It's a deliberate choice to stay within a genuinely mild, low-risk wellness dose, not a compromise.
The postconcussion systematic review recorded improvements at 30 sessions. The case study on inflammatory markers involved 40 sessions over 10 weeks. Both point toward a genuine course of sessions rather than a single visit, which is why our own Recovery Programs are structured the same way.
Related My BioHealth services
for session details, pricing and booking. Many clients pair HBOT with for complementary mechanisms. Not sure where to start? Our assessment matches you to a real plan.
References
- Systematic Review and Dosage Analysis: Hyperbaric Oxygen Therapy Efficacy in Mild Traumatic Brain Injury Persistent Postconcussion Syndrome. PubMed Central. View study →
- Case Report: Low pressure hyperbaric oxygen therapy as a potential alternative treatment for chronic inflammatory response syndrome. Frontiers in Immunology, 2025. View study →