What is Hyperbaric Oxygen Therapy (HBOT)?

What is Hyperbaric Oxygen Therapy?

Hyperbarics is a medical and scientific field that focuses on the therapeutic use of oxygen under high pressure. This treatment, known as Hyperbaric Oxygen Therapy (HBOT), involves breathing 100% pure oxygen in a pressurized room or chamber at 2.0ATA or greater pressure and has a range of applications, from treating decompression sickness in divers to promoting wound healing in patients with chronic conditions.

Why is Hyperbaric Oxygen Therapy applied?

Your tissues require sufficient oxygen to function properly. When they are injured, the need for oxygen increases significantly. HBOT enhances the oxygen-carrying capacity of your blood. Through repeated sessions, the temporary boost in oxygen levels promotes the restoration of normal tissue oxygenation, even after the completion of the therapy.

How to Prepare for HBOT

For the procedure, you will be given a hospital-approved gown or scrubs to wear instead of your regular clothing. To ensure safety, certain items such as lighters or battery-powered devices that generate heat are prohibited inside the hyperbaric chamber. Additionally, you may need to remove any hair and skin care products that are petroleum-based due to their potential fire hazard. Your healthcare team will provide specific instructions on how to prepare for hyperbaric oxygen therapy.

What to expect

During Hyperbaric Oxygen Therapy:

1. Individual Units (Monoplace Chambers): In these units, you lie on a table that slides into acrylic, aluminum and/or steel chamber.
2. Multiperson Units: These resemble large hospital rooms where several people can sit or lie down during the treatment. Oxygen is administered through a mask or a lightweight, clear hood placed over the head.
3. Mild hyperbaric chambers: Mild units treat under 2.0ATA, usually between 1.3-1.5ATA.  Mild units are only approved for treating acute mountain sickness with AIR (21%oxygen) and are currently considered subtherapeutic of all other conditions.  All FDA and UHMS approved indications require a minimum of 2.0ATA while breathing 100% pure oxygen. The FDA, AMA and UHMS have all issued statements about the lack of safety with these devices.  

During the session, the air pressure inside the chamber is increased to about 2 to 3 times higher than normal atmospheric pressure.

This increased pressure may cause a temporary sensation of fullness in your ears, similar to what you might experience during an airplane flight or at high altitudes. You can relieve this feeling by yawning or swallowing.

Hyperbaric oxygen therapy sessions typically last around two hours. Your healthcare team will monitor you and the therapy unit throughout the treatment.

After Hyperbaric Oxygen Therapy:

Following your session, your therapy team will perform a check-up, which may include examining your ears, taking your blood pressure and pulse, and checking your blood glucose if you have diabetes. Once you are cleared, you can get dressed and leave. You may feel somewhat tired or hungry after the treatment, but that should be the only side effect to deal with.

Results

To achieve the benefits of hyperbaric oxygen therapy, multiple sessions are usually required. The number of sessions depends on your medical condition. Some conditions, like carbon monoxide poisoning, might be treated in three visits, while others, such as nonhealing wounds, may need 40 or more treatments.

Hyperbaric oxygen therapy is often part of a comprehensive treatment plan that includes other therapies and medications tailored to your specific needs.

History of Hyperbarics

The use of high-pressure environments for medical treatment dates back to the 17th century. In 1662, a British physician named Nathaniel Henshaw constructed a sealed chamber called a “domicilium” to treat various conditions. The development of modern hyperbaric medicine, however, began in the early 20th century with the work of Orval Cunningham, who used a steel chamber to treat patients with the Spanish flu. The field expanded significantly during World War II when hyperbaric oxygen therapy was used to treat decompression sickness in divers and pilots. Since then, advances in technology and medical research have broadened the scope of hyperbarics to include a variety of medical conditions.

Mechanisms of Hyperbaric Oxygen Therapy

Hyperbaric Oxygen Therapy increases the amount of oxygen your blood can carry, enhancing the body’s natural healing processes. Under normal atmospheric conditions, oxygen is transported by red blood cells. However, in a hyperbaric chamber, the increased pressure allows more oxygen to dissolve in the plasma, which can diffuse more readily into tissues and cells.

FDA-Approved Applications of Hyperbaric Oxygen Therapy (HBOT)

These conditions have been officially cleared by the FDA for treatment with hyperbaric chambers. HBOT is recognized for its ability to deliver high concentrations of oxygen to damaged tissues, enhance healing, and fight infection.

‍Air or Gas Embolism

Air or gas embolism occurs when bubbles enter the bloodstream and block blood flow, which can result from trauma, surgery, or medical procedures. HBOT is the gold standard treatment, as it compresses gas bubbles and enhances oxygen delivery to affected tissues. It is particularly effective in treating cerebral air embolism, where it helps limit neurological damage. Prompt treatment is essential for improving recovery and reducing the risk of permanent complications.

Anemia (Severe, When Transfusions Cannot Be Used)

In cases of life-threatening anemia where blood transfusions are not an option—such as in patients who refuse transfusions—HBOT can sustain life by oxygenating plasma directly. Although it doesn’t replace red blood cells, it temporarily supplies vital oxygen to organs and tissues, buying time until the body can recover or other interventions become available. This application has proven life-saving in critical care settings.

Burns (Severe and Large, Treated at a Specialized Center)

HBOT plays a supportive role in the management of severe burns, especially when treated in specialized burn centers. It reduces swelling, fights infection, and accelerates tissue repair by increasing oxygen delivery to injured skin. Studies suggest that HBOT enhances the survival of skin grafts and helps reduce the need for surgical debridement. This adjunctive therapy is especially beneficial when burns affect large surface areas or involve deep tissue.

Carbon Monoxide Poisoning

Carbon monoxide binds to hemoglobin more readily than oxygen, leading to cellular hypoxia and potential brain damage. HBOT rapidly displaces carbon monoxide from the bloodstream, restoring oxygenation and preventing long-term cognitive effects. Clinical trials have shown that early HBOT reduces the risk of memory loss, confusion, and motor deficits. It’s considered the most effective treatment for moderate to severe carbon monoxide poisoning, especially with neurological symptoms.

Crush Injury

Crush injuries result in extensive soft tissue damage, often leading to inflammation, ischemia, and the risk of compartment syndrome. HBOT helps reduce edema, promote tissue oxygenation, and prevent cell death. It also enhances the body’s natural healing response and reduces the risk of infection. This therapy is especially useful when surgery alone may not be sufficient to preserve tissue viability or limb function.

Decompression Sickness (Diving Risk)

Decompression sickness, or “the bends,” is caused by nitrogen bubbles forming in the blood due to rapid ascent in divers. HBOT is the standard emergency treatment, as it reduces bubble size and improves oxygen delivery. It also alleviates symptoms like joint pain, dizziness, paralysis, and fatigue. This therapy has been used for decades by military and civilian dive teams, with consistent, life-saving results.

Gas Gangrene

Gas gangrene is a rapidly spreading bacterial infection that produces toxins and gas in tissues, typically after trauma or surgery. HBOT slows disease progression by inhibiting anaerobic bacteria and boosting white blood cell activity. It enhances the effectiveness of antibiotics and supports wound healing by supplying high oxygen concentrations. Used alongside surgical and antibiotic treatments, HBOT can significantly improve outcomes and reduce the need for amputation.

Hearing Loss (Sudden, Sensorineural)

Sudden sensorineural hearing loss (SSNHL) is an unexpected loss of hearing in one ear, often with no known cause. When administered within the first two weeks of onset, HBOT can help restore hearing by improving oxygenation in the inner ear and reducing inflammation. It is typically used in conjunction with corticosteroids and has shown greater efficacy when started early, offering a non-invasive option to aid recovery.

Infection of Skin and Bone (Severe)

Chronic or severe infections of the skin and bones, such as refractory osteomyelitis, can resist conventional treatments. HBOT enhances the immune system’s ability to fight these infections by improving oxygen supply to infected tissues. It also promotes angiogenesis and collagen production, which support wound healing. When used with antibiotics and surgical care, HBOT can help resolve stubborn infections and reduce recurrence.

Radiation Injury (Soft Tissue and Bone)

Radiation therapy can damage surrounding healthy tissues, leading to delayed healing, fibrosis, and chronic pain. HBOT stimulates new blood vessel formation and improves oxygen delivery in irradiated areas, facilitating tissue regeneration. It's commonly used for complications such as osteoradionecrosis (bone death) or radiation cystitis. This therapy improves patient quality of life and supports long-term recovery from radiation-related injuries.

Skin Graft Flap (At Risk of Tissue Death)

When skin grafts or flaps show signs of failing due to poor blood flow, HBOT can help salvage the tissue by increasing oxygen tension in ischemic areas. It reduces swelling, supports capillary growth, and prevents necrosis. Used as an adjunct to surgical care, HBOT improves graft take rates and enhances the healing of complex reconstructions, particularly in cases involving trauma, cancer resection, or burns.

Vision Loss (Sudden, Painless in One Eye)

Central retinal artery occlusion (CRAO) can cause sudden, painless vision loss due to blocked blood flow to the retina. HBOT may help salvage vision by supplying oxygen directly to the retina before irreversible damage occurs. While not universally effective, early intervention increases the chances of visual recovery. It remains one of the few potential treatments for this ophthalmologic emergency.

Wounds (Non-Healing, Especially Diabetic Ulcers)

Chronic wounds—especially diabetic foot ulcers—often suffer from low oxygen levels, infection, and poor circulation. HBOT promotes healing by increasing tissue oxygenation, reducing inflammation, and supporting new blood vessel growth. Clinical trials have shown improved wound closure rates, reduced amputation risk, and enhanced patient outcomes. It is widely used in wound care centers as an adjunct to debridement, antibiotics, and pressure offloading.

Emerging or Experimental Applications of HBOT

These uses of HBOT are not FDA-approved but are currently being explored through research and clinical practice for their potential therapeutic benefits.

Chronic Infections

In treatment-resistant infections—especially where biofilm-forming bacteria are involved—HBOT offers promise by enhancing white blood cell activity and boosting the effects of antibiotics. It improves tissue oxygenation in hypoxic areas where infections thrive, helping suppress bacterial growth and support immune response. Clinical use includes osteomyelitis, necrotizing fasciitis, and soft-tissue infections where traditional treatments fail. While results are encouraging, more standardized trials are needed for regulatory approval.

Infections (General and Anaerobic)

Hyperbaric oxygen therapy can enhance the body’s ability to fight certain infections, particularly those caused by anaerobic bacteria that thrive in low-oxygen environments. For example, studies show that HBOT enhances the repair processes by modulating various cellular activities, including transcription, signaling, stress responses, apoptosis, and inflammation. It upregulates repair processes and downregulates mechanisms that perpetuate tissue damage. Specifically, HBOT influences pathways involving oxidative stress, inflammation, cell growth, and stem cell mobilization, thereby aiding in the regeneration of neural, bone, cartilage, muscle, cardiac tissue, and the intestinal barrier.

Stroke and Neurodegenerative Diseases

Research is ongoing, but some studies suggest that HBOT may improve outcomes in patients with strokes or neurodegenerative diseases by promoting neuroplasticity and reducing inflammation. Studies suggest HBOT improved neurological function and quality of life in post-stroke patients. Furthermore, another study demonstrates that HBOT significantly enhances spatial learning and memory in rats with amnestic mild cognitive impairment (aMCI). HBOT reduced neuronal apoptosis in the hippocampus and decreased the expression of pro-apoptotic proteins Fas and FasL, suggesting that HBOT can mitigate cognitive decline associated with aMCI by protecting neuronal health.

Traumatic Brain Injury (TBI)

Growing evidence shows that HBOT can improve cognitive function and reduce symptoms in patients with traumatic brain injuries by enhancing oxygen delivery to the brain involving the TrkB signal pathway. Various studies reported improved mental and functional outcomes in chronic traumatic brain injury patients treated with HBOT, and it was concluded that HBOT can improve cognitive functions in patients with vascular dementia.

Benefits of Hyperbaric Oxygen Therapy

Accelerated Healing

Hyperbaric oxygen therapy (HBOT) significantly accelerates the healing process by increasing oxygen concentration in the blood, which enhances tissue repair and reduces inflammation. This is particularly beneficial for chronic wounds, diabetic foot ulcers, and radiation injuries where conventional treatments have failed. Studies have shown that HBOT can improve wound healing rates and reduce recovery times.

Improved Quality of Life

For patients suffering from chronic pain, non-healing wounds, or traumatic injuries, HBOT can lead to substantial improvements in quality of life. By reducing pain and inflammation, enhancing mobility, and speeding up the overall recovery process, patients can experience a return to daily activities and an overall sense of well-being. For instance, patients with fibromyalgia have reported reduced pain levels and increased function after undergoing HBOT.

Non-Invasive Treatment

HBOT is a noninvasive treatment that can be seamlessly integrated with other therapies, such as physical therapy, medications, and surgical interventions. Its noninvasive nature makes it a preferred option for patients who are unable to undergo surgical procedures or who have not responded well to other treatments. Generally well-tolerated, HBOT poses a low risk of serious side effects, making it suitable for a wide range of patients, including those with compromised health conditions.

Enhanced Immunity and Infection Control

Hyperbaric oxygen therapy has antimicrobial effects that can inhibit certain bacteria’s growth and enhance antibiotics’ effectiveness. This makes HBOT an effective adjunct therapy for treating infections such as osteomyelitis and necrotizing fasciitis. By boosting the body’s immune response and promoting better blood flow to infected tissues, HBOT helps in faster recovery from infections.

Neuroprotection and Cognitive Benefits

Research suggests that HBOT can provide neuroprotective benefits, potentially aiding in the recovery of patients with traumatic brain injuries, strokes, and neurodegenerative diseases. By enhancing oxygen delivery to the brain, HBOT promotes neuroplasticity, reduces cerebral edema, and supports cognitive function recovery. Some studies have shown improvements in memory, attention, and executive functions in patients undergoing HBOT for brain injuries.

Anti-Inflammatory Effects

HBOT reduces systemic inflammation, which is a common underlying factor in many chronic conditions. By decreasing inflammatory cytokines and oxidative stress, HBOT helps manage conditions such as rheumatoid arthritis, Crohn’s disease, and other inflammatory disorders. This reduction in inflammation can lead to decreased pain and improved overall health.

Cosmetic and Dermatological Benefits

HBOT is increasingly being used in cosmetic and dermatological practices to enhance skin health. It promotes collagen production, reduces scarring, and improves the skin’s overall appearance. Patients with acne, rosacea, and psoriasis conditions may find relief and cosmetic improvement through HBOT treatments.

Risks and Contraindications

While hyperbaric oxygen therapy is generally safe, it is not without risks. Potential side effects and contraindications include:

Barotrauma

The high-pressure environment can cause damage to the ears, sinuses, and lungs, particularly if pressure changes are not managed carefully.

Oxygen Toxicity

Breathing pure oxygen at high pressures can lead to oxygen toxicity, which can cause seizures and other serious complications. Studies outline the mechanisms and prevention measures for oxygen toxicity.

Claustrophobia

Some patients may experience claustrophobia in the confined space of a hyperbaric chamber.

Specific Contraindications

Certain conditions, such as untreated pneumothorax (collapsed lung) and some types of chemotherapy, are contraindications for HBOT.

Future of Hyperbarics

The future of hyperbaric medicine looks promising, with ongoing research exploring new applications and refining existing treatments. Advances in technology, such as portable hyperbaric chambers and improved monitoring systems, are making HBOT more accessible and safer for patients.

Emerging Applications

Researchers are investigating the potential of HBOT in treating a variety of conditions, including:

• Autism Spectrum Disorders. Preliminary studies suggest that HBOT may improve cognitive and behavioral outcomes in children with autism. A study published in BMC Pediatrics showed significant improvements in social skills and cognitive function in autistic children undergoing HBOT. Furthermore, a more recent study found significant improvements in verbal communication skills among the children who underwent HBOT, suggesting that this therapy may enhance verbal abilities in ASD patients.
• Sports Injuries. Athletes increasingly use HBOT to speed up recovery from injuries and improve performance. Studies demonstrated significant reductions in pain and muscle injury markers (creatine phosphokinase, glutamic oxaloacetate transaminase, myoglobin) in the HBOT group compared to the control group, with improvements sustained for two weeks post-treatment.
• Anti-Aging. Some researchers believe HBOT could have anti-aging effects by promoting cellular repair and reducing inflammation. Studies showcase a positive impact on cognition, skin rejuvenation, metabolic regulation, musculoskeletal restoration, and cardiopulmonary function improvement.

Integration with Other Therapies

Physical Therapy

Combining HBOT with physical therapy can significantly accelerate recovery from musculoskeletal injuries. HBOT promotes angiogenesis and reduces inflammation, which complements physical therapy by improving tissue oxygenation and reducing pain, leading to more effective rehabilitation. This integrated approach is particularly beneficial for patients with chronic conditions like stroke, peripheral vascular disease, and spinal cord injuries, enhancing their mobility and recovery rate.

Pharmacological Treatments

HBOT can enhance the efficacy of certain medications. For instance, it increases the effectiveness of antibiotics and anti-inflammatory drugs by improving tissue oxygenation and reducing inflammation. This synergy is particularly useful in treating infections and chronic inflammatory conditions. Additionally, combining HBOT with neuroprotective drugs can offer added benefits in managing neurodegenerative diseases like Alzheimer’s and Parkinson’s by improving oxygen supply to the brain and reducing oxidative stress.

Surgical Interventions

HBOT is beneficial when used pre-and post-operatively. Pre-operative HBOT enhances tissue oxygen saturation, potentially reducing surgical complications. Post-operative HBOT accelerates wound healing, reduces infection risks, and minimizes recovery time. In reconstructive and plastic surgeries, HBOT supports tissue regeneration and improves the viability of grafts and flaps, leading to better surgical outcomes.

Stem Cell Therapy

HBOT can significantly enhance stem cell efficacy, mobilizing and improving the function of stem cells and increasing their survival and differentiation. This makes HBOT a valuable adjunct in stem cell therapies, improving outcomes in regenerative medicine by promoting angiogenesis and reducing inflammation, thereby supporting the therapeutic effects of stem cell treatments.

Oncology

In cancer treatment, HBOT can increase the efficacy of radiotherapy and chemotherapy by improving oxygen levels in tumors, making cancer cells more susceptible to these treatments. It also helps mitigate some adverse effects of cancer treatments, such as radiation-induced tissue damage, by promoting healing and reducing inflammation. Furthermore, studies suggest that HBOT may reduce growth in some cancer types, such as breast cancer.

Chronic Conditions Management

For chronic conditions like diabetes and cardiovascular diseases, HBOT can be integrated with conventional treatments to improve outcomes. In diabetic patients, especially those with non-healing wounds, HBOT significantly enhances wound healing and reduces severe complications. Combining HBOT with standard therapies improves myocardial oxygenation, reduces ischemia, and enhances overall cardiac function in cardiovascular diseases.

Conclusion

As scientific research and technological innovations progress, the scope and efficacy of HBOT are anticipated to expand. Future studies will likely refine treatment protocols, optimizing oxygen pressures, session durations, and frequencies tailored to specific conditions and patient populations. These advancements will undoubtedly enhance the therapeutic arsenal available to healthcare professionals, solidifying HBOT’s status as a cornerstone of contemporary medical practice. Integrating HBOT with other therapeutic modalities promises to amplify its benefits further, fostering holistic and improved patient outcomes across a broad spectrum of medical disciplines.