HBOT Terms Glossary: Hyperbaric Words Explained
Plain-language definitions of the hyperbaric oxygen therapy terms you will encounter, from ATA and monoplace to UHMS accreditation and prior authorization.
Hyperbaric oxygen therapy comes with its own vocabulary, and the unfamiliar terms can make the whole subject harder to understand than it needs to be. This glossary defines the words you are most likely to encounter when reading about HBOT or talking to a clinic, in plain language. It is general educational information, not medical advice. For anything specific to your care, your treatment team is the right source.
Treatment and Equipment Terms
Hyperbaric oxygen therapy (HBOT) is a medical treatment in which you breathe oxygen at a pressure higher than normal atmospheric pressure, which raises the oxygen levels in your body. Our what is HBOT guide covers the basics.
ATA (atmospheres absolute) is the unit used to describe the pressure inside a hyperbaric chamber. Normal pressure at sea level is one ATA, and treatment is delivered at a higher pressure, with the specific level set by the protocol for the condition.
Monoplace chamber is a hyperbaric chamber built for one person, who lies inside a clear tube that is pressurized. Multiplace chamber is a larger chamber that can hold several people at once, where patients breathe oxygen through masks or hoods. Our guide on monoplace versus multiplace compares them.
Medical-grade chamber refers to the hard-sided, higher-pressure chambers used in medical HBOT, as opposed to the low-pressure soft chambers sometimes called mild hyperbaric chambers, a distinction our mild versus medical-grade guide explains.
Air break is a scheduled period during a session when you breathe regular air instead of the treatment oxygen, built into some protocols for safety reasons related to oxygen exposure, as our oxygen toxicity guide describes.
Clinical and Safety Terms
Indication means a condition that a treatment is used for. An approved indication or FDA-approved use is a condition for which HBOT has regulatory clearance as safe and effective.
Off-label or investigational use means using HBOT for a condition outside the approved indications, where the evidence is generally preliminary and not established, the focus of our off-label HBOT guide.
Contraindication is a condition or factor that makes a treatment inadvisable or requires special caution. Our contraindications guide covers what this means for HBOT.
Barotrauma is a pressure-related injury, most commonly to the ears or sinuses, that can occur when air-filled spaces do not equalize properly to the pressure change. Equalization is the process of letting air move in and out of your ears and sinuses so they adjust to the changing pressure, the skill our first session guide prepares you for.
Oxygen toxicity is a rare potential side effect from oxygen exposure at high pressure, which medical protocols are designed to prevent, explained in our oxygen toxicity guide.
Provider and Coverage Terms
UHMS (Undersea and Hyperbaric Medical Society) is the professional body for hyperbaric medicine, which runs a facility accreditation program. UHMS accreditation means a facility has been reviewed against UHMS standards, a credential our guides on what UHMS is and verifying credentials discuss.
Prior authorization is approval that an insurer requires before a treatment, obtained in advance based on documentation, as our insurance approval and appeals guide explains. Treatment given without required prior authorization may not be covered.
Medical necessity refers to whether a treatment is appropriate and necessary for a condition under the insurer’s criteria, which the documentation must establish for a covered claim.
National Coverage Determination (NCD) is the Medicare policy that defines what Medicare covers for a given service. Medicare’s NCD for HBOT, viewable through CMS, lists the conditions Medicare covers.
Coinsurance, copay, and deductible are the parts of a covered treatment’s cost that you pay yourself, which contribute to out-of-pocket cost even when insurance pays its share, as our paying out of pocket guide discusses.
Using This Glossary
These definitions are meant to make reading about HBOT and talking with a clinic easier by demystifying the vocabulary. When you encounter a term you do not recognize, whether in a clinic’s materials, an insurance document, or one of our guides, this glossary is a place to check what it means in plain language.
Understanding the words is part of being an informed patient, but it is not a substitute for guidance from your own healthcare providers, who can apply these concepts to your specific situation. If a term comes up in the context of your care that you do not understand, asking your treatment team to explain it is always reasonable, the kind of straightforward question our questions to ask guide encourages. This page offers general educational definitions rather than medical advice.
Medical Disclaimer: This page provides general educational definitions related to hyperbaric oxygen therapy. It is not medical advice. Consult your qualified healthcare provider for guidance on your specific situation.
Sources: Undersea and Hyperbaric Medical Society | CMS, National Coverage Determination for Hyperbaric Oxygen Therapy (20.29)
Related guides: What Is HBOT? | How HBOT Works | Questions to Ask