Hyperbaric oxygen therapy: what it's used for and what to know

How HBOT works

In a hyperbaric chamber, the air pressure is raised to about two to three times normal while you breathe pure oxygen. That lets your blood carry much more oxygen to tissues, which may help fight some infections, reduce swelling and support healing.

HBOT chambers are Class II medical devices that FDA clears through the 510(k) process.

Established medical uses

The Undersea and Hyperbaric Medical Society (UHMS), the main professional body for hyperbaric medicine, lists these indications:

• Air or gas embolism and decompression sickness
• Carbon monoxide poisoning, including with cyanide poisoning
• Gas gangrene and necrotizing soft tissue infections
• Crush injuries, compartment syndrome and other acute traumatic loss of blood flow
• Central retinal artery occlusion (sudden vision loss from a blocked artery)
• Selected problem wounds, such as some diabetic foot ulcers
• Severe anemia when transfusion isn't an option
• Brain abscess and bone infection that hasn't responded to other care
• Delayed radiation injury to soft tissue or bone
• Compromised skin grafts and flaps
• Acute thermal burns
• Sudden sensorineural hearing loss with no known cause
• Avascular necrosis (bone death from lost blood supply)

How practitioners use it and what a session is like

Most people get HBOT as outpatients, and Cleveland Clinic says many who benefit have chronic wounds. Some wellness centers and med spas also offer it for goals outside the established list, covered in the next section.

• Before: you change into a hospital gown and leave metal objects and electronic devices outside the chamber.
• The chamber: some chambers hold one person. Larger ones hold several people, who breathe the oxygen through a mask or a clear hood.
• During: as the pressure rises, your ears may feel full. Yawning or a sip of water helps. Sessions usually last one to two hours, and people watch TV, sleep or listen to music.
• After: staff lower the pressure slowly, then check your vital signs and ears. You may feel sleepy.
• How many: a provider may schedule sessions once a week or five days a week, for 30 or more in total for a chronic problem. An emergency like decompression sickness may need one longer session.

Other popular uses: what the research shows so far

Some wellness centers and med spas promote HBOT for autism, depression, migraines, stroke, anti-aging and more. Research on these uses is still early: Cleveland Clinic says there isn't enough yet to show it is safe and effective for them. UHMS calls HBOT for traumatic brain injury investigational.

Mild or soft-sided chambers, often sold for home or spa use, run at lower pressures. UHMS calls mild hyperbaric oxygen below 1.5 atmospheres absolute unproven. Using any chamber in place of proven care for a serious illness can mean delaying care that works.

Risks and who shouldn't use it

• Ear and sinus pressure injury: ear pain, bleeding or fluid in the ear, or a burst eardrum; sinus pain and congestion.
• Oxygen toxicity: cough and shortness of breath; rare seizures; severe cases can be fatal.
• Temporary nearsightedness: seen in 20% to 40% of people after 20 or more daily sessions, more often in people with diabetes or over 65. Vision usually recovers.
• Fire: pure oxygen makes things ignite easily. In August 2025 FDA told providers it is aware of reports of serious injuries and deaths, including fires, with HBOT devices. FDA believes these are uncommon but says they can and do occur.
• Claustrophobia and anxiety, especially in single-person chambers.

Cleveland Clinic says HBOT isn't suitable for people with a collapsed lung or lung disease that raises that risk (such as COPD or emphysema), a fever or cold, a recent ear injury or surgery, certain older pacemakers, or pregnancy, because it can reduce oxygen to the fetus.

Carbon monoxide poisoning and diving decompression sickness are emergencies. Call 911 for headache, dizziness, confusion or nausea after a possible carbon monoxide exposure, or joint pain, numbness or trouble breathing after diving.

Your call, with a good practitioner

Whether HBOT fits your goals is your decision. These questions help you choose a center:

1. Ask your clinician whether your condition is one HBOT is established for.
2. Ask whether the facility is accredited by UHMS, which sets accreditation criteria for hyperbaric facilities.
3. Ask who supervises each session, what chamber and pressure they use, and how many sessions they plan and why.
4. Ask about fire safety rules, such as keeping electronics and metal objects out of the chamber, and tell them about any skin care products you use, since pure oxygen can make them ignite more easily.

Red flags: a center that promises results for conditions outside the established list, can't name who supervises each session, or doesn't explain its fire safety rules.

Gabriel can find and book a qualified hyperbaric clinic for you. Read about hyperbaric oxygen sessions, or ask Gabriel free whether HBOT fits your situation.