HBOT for Wound Healing: How Hyperbaric Oxygen Accelerates Recovery

Hyperbaric oxygen therapy (HBOT) helps selected hard-to-heal wounds by raising the oxygen dissolved in blood plasma, which fuels new blood vessel growth, collagen production and infection control in oxygen-starved tissue. The strongest evidence is for diabetic foot ulcers: in the HODFU trial, Löndahl and colleagues (Diabetes Care, 2010) found that 52% of patients treated with HBOT healed fully at one year, compared with 29% of patients given a sham treatment.

HBOT, also written HBO2 or called hyperbaric oxygen, is an add-on to good wound care rather than a replacement for it. It is reserved for wounds that have stalled despite debridement, offloading and infection control, and it works only where some blood supply remains. The sections below cover how it works, which wounds qualify, what the trials show, what a course of treatment looks like, and how to find a hyperbaric wound center.

Why Wounds Fail to Heal

Normal wound healing follows a predictable sequence: hemostasis, inflammation, proliferation, and remodeling. When this cascade stalls, you get a chronic wound. In the United States alone, chronic wounds affect approximately 6.5 million people and cost the healthcare system over $25 billion annually, according to Sen and colleagues (Wound Repair and Regeneration, 2009).

The most common reason wounds become chronic is insufficient oxygen delivery to the wound bed. Oxygen is the fuel for nearly every step of wound healing: white blood cells need it to kill bacteria, fibroblasts need it to produce collagen, and new blood vessels need it to form. When local tissue oxygen levels drop below critical thresholds (typically below 30-40 mmHg), healing grinds to a halt.

Diabetes, peripheral arterial disease, prior radiation, smoking, venous disease and repeated pressure all lower oxygen delivery to the skin. Chronic infection and biofilm then consume what little oxygen arrives, which keeps the wound locked in the inflammatory phase.

This is exactly where hyperbaric oxygen therapy (HBOT) intervenes. For a complete overview of HBOT and its many applications, see our hyperbaric oxygen therapy guide.

How HBOT Accelerates Wound Healing: The Mechanisms

Hyperoxygenation

Under normal conditions, hemoglobin carries about 97% of the oxygen in your blood, with only a small amount dissolved directly in plasma. At 2.0-2.5 ATA (atmospheres absolute) breathing 100% oxygen, the amount of dissolved plasma oxygen increases dramatically. Tissue oxygen levels in the wound bed can rise from 10-20 mmHg (typical in chronic wounds) to 200-400 mmHg or higher during treatment.

This oxygen increase persists for hours after leaving the chamber, creating a therapeutic window during which cellular repair processes can run at full capacity.

Angiogenesis (New Blood Vessel Formation)

Chronic wounds are stuck in a hypoxic environment. HBOT creates alternating cycles of hyperoxia (during treatment) and relative hypoxia (between treatments). This cycling stimulates vascular endothelial growth factor (VEGF) production, which drives the formation of new capillaries into the wound bed.

New blood vessels mean lasting improvement in oxygen delivery, not just a temporary boost during each session. This is one of the reasons HBOT requires multiple sessions: angiogenesis is a cumulative process that builds over weeks of treatment.

Fibroblast Proliferation and Collagen Synthesis

Fibroblasts are the cells responsible for building the structural framework of healing tissue. They require oxygen to produce collagen (the main structural protein in healing tissue) and to proliferate. At oxygen tensions below 20 mmHg, fibroblast activity is severely impaired. HBOT restores oxygen to levels that support strong fibroblast function.

The collagen produced under adequate oxygen conditions is also stronger. Oxygen is a required cofactor for the hydroxylation of proline and lysine residues in collagen molecules, a step that is essential for proper cross-linking and tensile strength.

Enhanced White Blood Cell Function

Neutrophils (the body’s first-line infection fighters) require oxygen to generate reactive oxygen species (ROS) through the oxidative burst. This is their primary mechanism for killing bacteria. In hypoxic wounds, neutrophil killing capacity can drop by 50% or more.

HBOT restores neutrophil bactericidal function, which is particularly critical in infected or contaminated wounds. At the same time, the elevated oxygen levels are directly bactericidal to many anaerobic organisms that thrive in low-oxygen wound environments.

Conditions with Strong Evidence for HBOT Wound Healing

The Undersea and Hyperbaric Medical Society (UHMS) publishes the list of conditions its members treat with hyperbaric oxygen, and the UHMS indications list is the reference most US hospital wound centers follow. Four of those indications are chronic wound problems, described below. The FDA regulates the chambers themselves as medical devices.

Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are the most well-studied wound indication for HBOT. Diabetes impairs wound healing through multiple mechanisms: peripheral neuropathy, microvascular disease, immune dysfunction, and impaired growth factor signaling. The result is ulcers that resist conventional treatment and frequently lead to amputation.

The landmark trial is HODFU (Hyperbaric Oxygen Therapy in Diabetics with Chronic Foot Ulcers), a double-blind, placebo-controlled study published by Löndahl and colleagues in Diabetes Care (2010). It found that HBOT significantly increased complete healing of chronic DFUs compared with sham treatment with hyperbaric air. Later trials and meta-analyses support a benefit for selected patients, particularly with Wagner Grade 3 and 4 ulcers (deeper wounds with more extensive tissue involvement), though results are mixed, as the evidence section below explains.

The Undersea and Hyperbaric Medical Society (UHMS) and Medicare both recognize DFUs as an approved indication for HBOT when the ulcer has failed to respond to 30 days of standard wound care.

Delayed Radiation Injury

Radiation therapy saves lives but causes lasting damage to the vasculature and soft tissues in the treatment field. Radiation-induced endarteritis (inflammation and fibrosis of small blood vessels) creates progressive tissue hypoxia that can manifest months or years after treatment as non-healing wounds, osteoradionecrosis (bone death), or soft tissue radionecrosis.

HBOT is one of the few treatments that addresses the underlying pathology of radiation injury rather than just managing symptoms. By stimulating angiogenesis in irradiated tissue, HBOT can restore blood supply to levels that support healing. Our post on HBOT for radiation injury covers these indications in more depth.

Clinical evidence is strongest for:

• Mandibular osteoradionecrosis (jawbone death after head/neck radiation)
• Radiation cystitis (bladder injury after pelvic radiation)
• Radiation proctitis (rectal injury after pelvic radiation)
• Soft tissue radionecrosis of the chest wall after breast radiation

For radiation cystitis, the randomized RICH-ART trial reported by Oscarsson and colleagues (Lancet Oncology, 2019) found that HBOT relieved urinary symptoms more than standard care alone.

Compromised Skin Grafts and Flaps

Skin grafts and surgical flaps depend on rapid revascularization from the wound bed to survive. When this process is compromised (due to poor local blood supply, infection, or patient factors like diabetes or smoking), the graft or flap may fail.

HBOT supports graft and flap survival by maximizing oxygen delivery during the critical first days after surgery, enhancing angiogenesis, and reducing infection risk. It is used both as a preconditioning treatment (before surgery in irradiated or poorly vascularized tissue) and as a rescue intervention for failing grafts.

Chronic Refractory Osteomyelitis

Chronic bone infection that persists despite appropriate antibiotics and surgical debridement is another approved indication. HBOT enhances antibiotic effectiveness (many antibiotics require oxygen for their bactericidal activity), directly kills anaerobic bacteria, and supports the immune response needed to clear deep-seated bone infections.

Other wounds HBOT is used for

The UHMS list also includes acute wound problems where oxygen delivery is suddenly cut off: necrotizing soft tissue infections, gas gangrene, crush injuries and acute traumatic ischemia, and thermal burns. In these settings HBOT is usually given in a hospital alongside surgery and antibiotics. Readers dealing with a burn can see the burns treatment guide.

HBOT Wound Healing Protocols

Sessions are typically scheduled 5 days per week (Monday through Friday). Some protocols include Saturday sessions for acute or severe cases. The total number of sessions depends on wound response, measured through serial wound measurements, transcutaneous oximetry (TCOM), and clinical assessment.

What does the research show about HBOT for wound healing?

The evidence for HBOT in wound healing is real but mixed. The strongest support is for selected diabetic foot ulcers and late radiation injury, while several well run trials found little or no added benefit for other groups of patients.

The 2015 Cochrane review by Kranke and colleagues pooled 12 randomized trials with 577 participants. For diabetic foot ulcers, HBOT improved the rate of healing at six weeks, but that benefit was not evident at one year, and the difference in major amputation rates was not statistically significant.

Two later trials in diabetic patients were less encouraging. Fedorko and colleagues (Diabetes Care, 2016) randomized 107 patients to 30 sessions of HBOT or a sham and found no reduction in the need for amputation. The DAMO2CLES trial by Santema and colleagues (Diabetes Care, 2018) found that adding HBOT did not significantly improve healing or limb salvage in 120 patients with ischemic leg ulcers, and 35% of the HBOT group could not complete the planned course.

Prevention of jaw osteoradionecrosis is a good example of evidence shifting. The HOPON trial by Shaw and colleagues (International Journal of Radiation Oncology, Biology, Physics, 2019) found osteoradionecrosis in 6.4% of the HBOT group and 5.7% of controls after dental extractions, which challenged routine preventive HBOT before dental work in an irradiated jaw.

The practical reading is that patient selection matters. HBOT tends to help when tissue is oxygen starved but still has a usable blood supply, as shown on TCOM testing, and when it is added to complete wound care rather than used on its own.

Who is a good candidate for HBOT wound therapy?

A good candidate for HBOT wound therapy has a wound on the recognized indication list that has not healed with standard care, enough blood flow for oxygen to reach it, and no condition that makes pressurization unsafe. A wound care physician or hyperbaric medicine physician makes that call after an exam and testing.

Most hospital wound centers work through a similar sequence before the first session:

1. Confirm the diagnosis and grade the wound, for example with the Wagner scale for diabetic foot ulcers.
2. Document a trial of standard wound care, which Medicare sets at 30 days for diabetic foot ulcers.
3. Check circulation with vascular studies and TCOM, and refer to a vascular surgeon for revascularization when arteries are blocked.
4. Screen for contraindications, including an untreated pneumothorax (collapsed lung), which rules out treatment, plus ear, sinus, lung and seizure history and current medications.
5. Agree on a treatment plan with set points to reassess wound size and tissue oxygen.

The care team often includes a hyperbaric physician, a wound care nurse, a certified hyperbaric technologist who runs the chamber, and specialists such as podiatrists, vascular surgeons, plastic surgeons, radiation oncologists and urologists, depending on the wound.

Does insurance cover HBOT for wound healing?

Medicare and most commercial insurers cover HBOT for wound healing when the wound is on the approved list and coverage criteria are met. The rules are set out in the Medicare National Coverage Determination for Hyperbaric Oxygen Therapy (20.29), and many private plans follow the same criteria.

For diabetic foot ulcers, coverage generally requires a Wagner Grade 3 or higher wound and documented failure of 30 days of standard wound care, with ongoing reassessment during treatment. Prior authorization is common, and out-of-pocket costs depend on the plan. Our guide to HBOT costs explains what drives the bill.

Treatment outside the covered list, including most sessions at cash-pay wellness centers, is usually paid out of pocket. Uses that are not on the UHMS list are off label, and the evidence for them is thinner than for the wound indications described above.

How to find a hyperbaric wound center

Hyperbaric wound care is offered mainly through hospital-based wound centers and some outpatient hyperbaric facilities that run medical-grade chambers at 2.0 ATA or higher with 100% oxygen. When you compare options, ask whether a physician trained in hyperbaric medicine supervises every session, whether the facility holds UHMS accreditation, and whether it works with your wound care team and insurer.

You can browse hyperbaric oxygen therapy clinics across the US in the Regenerated.com directory, and read the HBOT treatment guide for indications, safety and session details beyond wound care. Listing order in the directory is not a paid ranking, Featured slots are clearly labeled and capped, and Verified means a clinic has completed credential checks, not that it paid more. Regenerated.com is free for patients, and inclusion in the directory is not an endorsement. The guide to Featured, Verified and organic listings explains each label.

Some listed clinics offer mild or soft-shell chambers aimed at wellness rather than wound care. Our comparison of mild HBOT and clinical HBOT explains why those are not interchangeable for a chronic wound.

What to Expect During Treatment

You enter a hyperbaric chamber (either a monoplace chamber for one person or a multiplace chamber for several) and breathe 100% oxygen while the pressure gradually increases. The experience is similar to being in an airplane cabin during descent: you will feel pressure changes in your ears and may need to equalize by swallowing, yawning, or performing a Valsalva maneuver.

Most sessions last 90-120 minutes at treatment depth. You can typically read, watch TV, or sleep during treatment. The compression and decompression phases add about 15-20 minutes to total time in the chamber.

What happens at a typical wound session?

A typical wound session follows the same routine each day. Staff check your blood sugar if you have diabetes, review your medications and ask about ear or sinus congestion. You change into cotton clothing, because lighters, phones, lotions and other fire risks are not allowed in a pure oxygen environment.

In a monoplace chamber the whole clear tube fills with oxygen. In a multiplace chamber you breathe oxygen through a hood or mask, with scheduled air breaks to lower the risk of oxygen toxicity. Your wound team usually measures and photographs the wound between sessions to track progress.

Risks and Side Effects

HBOT is generally well tolerated at standard wound care pressures, but it does carry some risks:

• Barotrauma: Ear or sinus pain from pressure changes (most common side effect). Usually manageable with equalization techniques.
• Oxygen toxicity: At very high doses, oxygen can cause seizures. This is rare at standard treatment pressures and is minimized by incorporating air breaks during the session.
• Myopia: Temporary nearsightedness can develop after 20+ sessions. This typically reverses within weeks to months after treatment ends.
• Claustrophobia: Monoplace chambers can trigger anxiety in claustrophobic individuals. Multiplace chambers are a better option for these patients.
• Low blood sugar: People with diabetes can see blood glucose fall during treatment, which is why many centers check it before and after each session.

In the RICH-ART trial, 41% of patients in the HBOT group had transient, mild to moderate side effects related to sight and hearing, according to Oscarsson and colleagues (2019). An untreated pneumothorax rules out HBOT, and certain chemotherapy drugs, pregnancy, uncontrolled seizures and severe lung disease need a careful review first. Our post on hyperbaric chamber side effects covers each risk in more detail.

Frequently Asked Questions

Does insurance cover HBOT for wound healing?

Yes, for approved indications. Medicare covers HBOT for diabetic foot ulcers (Wagner Grade 3+), chronic refractory osteomyelitis, compromised grafts/flaps, delayed radiation injury, and several other conditions under its national coverage determination. Most commercial insurers follow Medicare guidelines. Prior authorization is usually required, along with documentation that 30 days of standard wound care has failed. Sessions for uses outside the covered list are usually paid out of pocket.

How long does it take to see wound improvement?

Most patients begin to see measurable wound changes (reduced wound size, healthier granulation tissue, decreased drainage) within 10-15 sessions. Full healing may take the entire 20-40 session course or longer for severe wounds. Healing often continues for weeks after the last session, because the new blood vessels built during treatment keep supplying the wound. Your team reassesses at set points and stops treatment if the wound is not responding.

Can I do HBOT at home with a mild hyperbaric chamber?

Mild hyperbaric chambers (also called soft chambers) operate at 1.3-1.5 ATA with concentrated ambient air rather than 100% oxygen. They deliver a fraction of the oxygen dose of clinical-grade chambers. For serious wound healing applications, they are not considered equivalent to medical-grade HBOT at 2.0+ ATA with 100% oxygen. Insurance will not cover soft chamber treatments, and a chronic wound still needs regular review by a wound care clinician.

Are there wounds that HBOT cannot help?

HBOT cannot help a wound that has no remaining blood supply, because oxygen still has to travel through the blood to reach the tissue. In cases of complete arterial occlusion (such as advanced peripheral arterial disease with no runoff vessels), HBOT alone cannot deliver oxygen to the wound. Vascular assessment and, if possible, revascularization should precede or accompany HBOT in these cases. TCOM testing helps show which wounds are likely to respond.

Can HBOT be combined with other wound treatments?

Yes, HBOT is designed to be combined with other wound treatments. It is typically used alongside standard wound care (debridement, offloading, moist wound management, infection control) rather than as a standalone treatment. It is an adjunct that addresses the oxygen deficit while other treatments manage the wound locally. Stopping offloading or skipping dressing changes during an HBOT course usually undermines the result, so both parts of the plan need to continue.

How many total sessions are usually needed?

This varies by condition and individual response. Diabetic foot ulcers typically require 20-40 sessions, and the HODFU trial used 40. Radiation injuries may need 30-60. Your provider will assess progress every 10-15 sessions and adjust the treatment plan accordingly. Some facilities use intermittent TCOM testing to objectively monitor tissue oxygen improvements. Sessions usually run five days a week, so a full course often takes six to twelve weeks.