What Is Hyperbaric Oxygen Therapy? Complete Guide

Hyperbaric oxygen therapy (HBOT) uses pressurized oxygen to promote healing. Learn how it works, what conditions it treats, costs, and what to expect.

Updated February 22, 2026 4 min read
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any treatment. Read full disclaimer.

What is hyperbaric oxygen therapy? It’s a medical treatment where you breathe 100% pure oxygen inside a pressurized chamber. The pressure is raised to 2-3 times normal atmospheric pressure. That combination drives far more oxygen into your body than breathing regular air ever could.

FDA clearance applies to devices and their labeled intended uses. Clinical recommendations and insurance coverage must be checked separately.

How Hyperbaric Oxygen Therapy Works

During a session, the chamber pressure rises to 2.0-3.0 atmospheres absolute (ATA). At normal pressure, your lungs absorb oxygen mostly through red blood cells. At 2-3 ATA, your lungs can absorb 10-15 times more oxygen than usual.

That extra oxygen dissolves directly into your blood plasma. Plasma can carry oxygen even into areas with poor blood flow, where red blood cells can’t always reach.

Once there, that high-concentration oxygen does several things:

  • Angiogenesis: Stimulates new blood vessel growth.
  • Collagen synthesis: Speeds up tissue repair.
  • Infection control: Helps white blood cells kill certain bacteria more effectively.
  • Inflammation: Reduces swelling in damaged tissue.

These effects are why HBOT is used for wound healing, infections, and tissue recovery, not just oxygen delivery.

What Conditions Does HBOT Treat?

FDA device labeling, UHMS clinical indications and CMS coverage criteria are distinct. This page does not present them as a single approval list. Consult the FDA device safety guidance and Medicare coverage guide for their respective purposes.

Off-label uses: Researchers are studying HBOT for traumatic brain injury, Long COVID, stroke recovery, and other conditions. Evidence and eligibility vary by indication; a research study does not establish device labeling or insurance coverage.

See the full breakdown at Conditions Treated with HBOT.

What Does an HBOT Session Look Like?

Before your first session, you’ll meet with a hyperbaric physician. They’ll review your medical history and confirm HBOT is appropriate for you.

Chamber types: Most facilities use monoplace chambers (one person, clear acrylic tube) or multiplace chambers (multiple patients, walk-in room). Both deliver the same therapeutic effect.

During your session:

  • Sessions last 90-120 minutes, including pressurization and depressurization time.
  • Pressure reaches 2.0-3.0 ATA depending on your condition.
  • You breathe 100% oxygen through a mask or hood inside the chamber.
  • You can watch TV, rest, or sleep.
  • You’ll need to equalize your ears as pressure rises, just like on an airplane.

Most people tolerate sessions well. Ear pressure is the most common complaint. Staff are always nearby and can adjust the session if needed.

See a full walkthrough at What to Expect at Your First Session.

Is HBOT Covered by Insurance?

Coverage depends on the specific diagnosis, criteria, provider and plan. Check CMS NCD 20.29 and your insurer; FDA device clearance alone does not establish coverage.

Off-label uses aren’t covered. If you’re seeking HBOT for TBI, Long COVID, or wellness purposes, expect to pay out of pocket.

Learn more:

Frequently Asked Questions

Is hyperbaric oxygen therapy safe?

Yes, for most people. The most common side effect is ear pressure during pressurization. Serious complications like oxygen toxicity are rare at medical facilities. Before your first session, your provider will screen you for contraindications, such as certain lung conditions or medications that don’t mix with high-pressure oxygen.

How many HBOT sessions are needed?

It depends on the condition. Carbon monoxide poisoning typically requires 1-3 sessions. Wound healing protocols usually call for 20-40 sessions. Radiation injury may require up to 60 sessions. See the full breakdown at How Many Hyperbaric Treatments Do You Need?

Is HBOT the same as a home oxygen concentrator?

No. Home “hyperbaric” units typically operate at around 1.3 ATA and deliver 24-35% oxygen. Medical HBOT runs at 2.0-3.0 ATA with 100% oxygen. That’s not a small difference. The therapeutic effects documented in clinical research come from medical-grade pressure and oxygen levels.

Where can I find an HBOT provider?

Start with Find a Provider Near You. Look for facilities accredited by the Undersea and Hyperbaric Medical Society (UHMS) and staffed by a physician credentialed in hyperbaric medicine.

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Medical Disclaimer: This page is for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before pursuing any medical treatment.