Clinical Evidence

Indications

HBOT applications across the evidence spectrum — from FDA-approved standard-of-care conditions recognised by the UHMS to emerging investigational uses with preliminary clinical evidence.

FDA-Approved Indications

The Undersea and Hyperbaric Medical Society (UHMS) recognizes 14 conditions for which HBOT is approved as a standard-of-care treatment, with evidence levels ranging from A (strong RCT evidence) to B (observational/expert consensus).

Acute Ischemias

1 Level A

Acute Ischemias

Air or Gas Embolism

Intravascular gas bubbles causing arterial obstruction. HBOT reduces bubble volume and promotes nitrogen elimination.

Standard of Care

4 Level A

Acute Ischemias

Crush Injury & Compartment Syndrome

Reduces post-ischemic edema, preserves threatened tissue, and accelerates healing in traumatic crush injuries.

Standard of Care

12 Level B

Acute Ischemias

Compromised Skin Grafts & Flaps

Salvage therapy for ischemic skin grafts and flaps. Reduces hypoxic necrosis and promotes graft survival through enhanced oxygenation.

Standard of Care

Toxicities

2 Level A

Toxicities

Carbon Monoxide Poisoning

HBOT accelerates CO elimination from hemoglobin and cytochrome oxidase, preventing delayed neurological sequelae.

Standard of Care

Infectious Diseases

3 Level A

Infectious Diseases

Clostridial Myositis & Myonecrosis (Gas Gangrene)

HBOT is directly lethal to Clostridium perfringens and inhibits toxin production, used adjunctively with surgery and antibiotics.

Standard of Care

7 Level B

Infectious Diseases

Exceptional Blood Loss Anemia

When transfusion is not possible due to religious beliefs or unavailability, HBOT provides sufficient dissolved plasma oxygen to sustain life.

Standard of Care

8 Level B

Infectious Diseases

Intracranial Abscess

Adjunctive therapy for brain abscesses, particularly those caused by anaerobic organisms. Enhances antibiotic efficacy and immune response.

Standard of Care

9 Level A

Infectious Diseases

Necrotizing Soft Tissue Infections

Adjunctive treatment for necrotizing fasciitis and Fournier's gangrene, reducing mortality and tissue loss when combined with surgery.

Standard of Care

10 Level A

Infectious Diseases

Refractory Osteomyelitis

Chronic osteomyelitis unresponsive to conventional therapy. HBOT enhances leukocyte killing, promotes angiogenesis in avascular bone.

Standard of Care

Gas/Bubble Disorders

5 Level A

Gas/Bubble Disorders

Decompression Sickness

Primary treatment for nitrogen bubble formation in divers and compressed-air workers. Reduces bubble volume and promotes nitrogen elimination.

Standard of Care

Wound Healing

6 Level A

Wound Healing

Enhancement of Healing in Selected Problem Wounds

Adjunctive treatment for chronic non-healing wounds, particularly diabetic foot ulcers with transcutaneous oxygen measurements <40 mmHg.

Standard of Care

11 Level A

Wound Healing

Delayed Radiation Injury (Soft Tissue & Bony Necrosis)

Treatment for osteoradionecrosis and soft tissue radiation necrosis. Promotes angiogenesis in hypoxic, hypovascular, hypocellular tissue.

Standard of Care

Sensory Disorders

13 Level B

Sensory Disorders

Idiopathic Sudden Sensorineural Hearing Loss

Adjunctive treatment when corticosteroids fail. Reverses cochlear hypoxia and reduces endolymphatic hydrops.

Standard of Care

14 Level B

Sensory Disorders

Central Retinal Artery Occlusion

Emergency treatment to preserve retinal layers and improve visual acuity through reversal of retinal ischemia.

Standard of Care

All 14 indications are recognized by the Undersea and Hyperbaric Medical Society (UHMS) and covered by Medicare/Medicaid in the United States. Evidence levels follow UHMS grading criteria.

Emerging Evidence

Conditions where preliminary clinical evidence supports investigational use of HBOT. Evidence levels remain B or C; independent replication of single-group findings is generally awaited.

Post-Viral Syndromes

15 Level B

Post-Viral Syndromes

Long COVID

Persistent multisystem symptoms following acute SARS-CoV-2 infection — including fatigue, cognitive dysfunction ("brain fog"), sleep disturbance, and pain. A 2022 randomised controlled trial reported significant improvements in cognitive function, sleep, pain, and overall symptom burden after 40 HBOT sessions, with benefits sustained at one-year follow-up. The evidence base is currently anchored to a single research group; independent replication is awaited (HOT-LoCO trial in progress).

Emerging Evidence

Chronic Pain Syndromes

16 Level B

Chronic Pain Syndromes

Fibromyalgia

Chronic central sensitisation syndrome characterised by widespread pain, tender points, fatigue, sleep disturbance, and cognitive symptoms. A 2015 prospective controlled trial reported significant improvements in pain, tender points, quality of life, and brain activity patterns after 40 HBOT sessions at 2.0 ATA. Two independent 2023 meta-analyses pooled randomised data and confirmed improvements in function, tender points, fatigue, sleep, and quality of life — though the magnitude of pain reduction varied between pooled analyses. A separate 2023 RCT in fibromyalgia patients with a history of traumatic brain injury reported significant pain and symptom improvements with HBOT compared to pharmacological treatment (60 sessions, 2.0 ATA). The seminal RCT remains anchored to a single research group, but meta-analytic confirmation provides supporting evidence.

Emerging Evidence

Inflammatory Skin Disease

17 Level C

Inflammatory Skin Disease

Inflammatory Dermatoses

Case-level and small-cohort evidence supports HBOT as an adjunct in selected inflammatory skin conditions, primarily atopic dermatitis and psoriasis. A 2025 review and a 2021 paediatric study describe reductions in pruritus, lesion severity, and Staphylococcus aureus colonisation in severe atopic dermatitis after HBOT cycles. Two 2009 case reports document remission of psoriasis vulgaris with HBOT (one pustular/arthropathic case after 6 sessions at 2.8 ATA × 60 min; one plaque case improving after 15 sessions at 2.0 ATA × 90 min). Other inflammatory dermatoses — hidradenitis suppurativa, livedoid vasculopathy, pyoderma gangrenosum — have been described in early-stage clinical reports but lack robust supporting trials. Protocols vary widely and are not standardised; HBOT is positioned as adjunctive, not first-line.

Emerging Evidence

Aesthetic & Reconstructive Surgery

18 Level B

Aesthetic & Reconstructive Surgery

Aesthetic & Reconstructive Recovery

Adjunctive HBOT in aesthetic and reconstructive surgery for accelerated post-procedure healing and salvage of compromised grafts and flaps. A 2023 case–control study of facelift patients (n=20, retrospectively matched, single surgeon) reported mean wound healing of 13.3 days in the HBOT group versus 36.9 days in matched controls (P<.001), with sessions starting within 24 hours of surgery at approximately 2.0 ATA. Reviews of compromised flaps and grafts characterise HBOT as a salvage adjunct that improves oxygen delivery, angiogenesis, fibroblast activity, and edema control while standard surgical management addresses the mechanical cause of failure. HBOT is positioned as a salvage and recovery adjunct, not as a routine enhancer of uncomplicated cosmetic surgery.

Emerging Evidence

Reproductive Health

19 Level C

Reproductive Health

Endometriosis

Endometriosis is an emerging investigational application of HBOT. Translational evidence in rodent models supports an anti-inflammatory effect on endometriotic lesions: a 2011 rat study reported lesion remission with HBOT, and a 2022 mouse-model study reported reduction of inflammatory markers. Clinical evidence in humans is awaited — the HEROES randomised trial (Sunnybrook Health Sciences Centre, NCT06579040, recruiting since April 2025) is currently underway to evaluate HBOT for endometriosis-related pain. HBOT is positioned as an investigational adjunct, not standard of care.

Investigational

Neuropsychiatric

20 Level B

Neuropsychiatric

Post-Traumatic Stress Disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder marked by intrusive memories, avoidance, hyperarousal, and altered mood and cognition, with documented changes in brain activity and white-matter integrity. A specific HBOT protocol has been studied as a means of inducing neuroplasticity in established, often treatment-resistant PTSD; rather than acting pharmacologically, it is proposed to drive neuroplasticity through the hyperoxic-hypoxic paradox, accompanied in trials by improved resting-state functional connectivity across the default-mode, central-executive and salience networks (2024) and increased white-matter fractional anisotropy in fronto-limbic tracts, the genu of the corpus callosum and the fornix on diffusion tensor imaging (2022). A randomised, sham-controlled trial in 56 combat veterans (60 sessions, 90 minutes, 100% O₂ at 2 ATA) found CAPS-5 scores fell from 42.6 to 25.8 with HBOT while the sham group did not improve; an earlier randomised controlled trial in treatment-resistant PTSD showed concordant symptom and neuroimaging improvements; a 2026 systematic review and meta-analysis pooled two sham-controlled PTSD RCTs and reported a large effect while cautioning that studies are small and preliminary; and a 2026 prospective observational cohort of 50 US veterans reported reductions sustained to six months. The investigational protocol as studied — not a clinical recommendation — comprised 60 daily sessions of 90 minutes, 100% oxygen at 2 ATA, with intermittent air breaks. The randomised evidence originates substantially from a single research group (Sagol Center / Shamir Medical Center) — the same lineage as the Long COVID and Fibromyalgia entries — though, unlike those, there is now early independent corroboration (a US observational cohort and a meta-analysis by an unaffiliated group). Sample sizes remain small and larger multicentre randomised trials are needed. HBOT for PTSD remains investigational and is not FDA-approved.

Emerging Evidence

These indications are not FDA-approved and are not currently covered by Medicare/Medicaid in the United States. They are presented for clinical context; treatment decisions require individual evaluation.