Hyperbaric Oxygen Therapy: Complete Guide to Uses & Benefits

What Is Hyperbaric Oxygen Therapy?

Hyperbaric oxygen therapy (HBOT) is a medical treatment where you breathe 100% pure oxygen inside a pressurized chamber at 1.5-3 times normal atmospheric pressure. This increases blood oxygen levels by 10-15 times, enabling enhanced tissue healing, fighting infections, and reducing swelling.

Hyperbaric oxygen therapy works on a fundamental principle of physics: under increased pressure, gases dissolve more readily into liquids. When you breathe pure oxygen in a pressurized environment, your blood plasma becomes saturated with oxygen molecules far beyond what normal breathing can achieve. This oxygen-rich blood then circulates throughout your body, delivering healing benefits to tissues that may be oxygen-starved due to injury, disease, or poor circulation.

The therapy has been used in medicine since the 1960s and has evolved from primarily treating divers with decompression sickness to becoming an established treatment for a wide range of medical conditions. Today, hyperbaric oxygen therapy is performed in thousands of hospital-based and freestanding facilities worldwide, with rigorous clinical evidence supporting its use for specific indications.

During treatment, you enter a hyperbaric chamber that can be designed for a single person (monoplace chamber) or multiple patients (multiplace chamber). The chamber is then pressurized with air or oxygen to the prescribed level, typically between 1.5 and 3 atmospheres absolute (ATA). At sea level, we experience approximately 1 ATA of pressure, so hyperbaric therapy effectively simulates being 5-20 meters underwater in terms of pressure exposure.

How Does HBOT Work at the Cellular Level?

The therapeutic effects of hyperbaric oxygen therapy stem from several physiological mechanisms that work together to promote healing. Understanding these mechanisms helps explain why HBOT is effective for certain conditions and not others.

Normally, oxygen travels through your bloodstream attached to hemoglobin molecules in red blood cells. Under normal conditions, hemoglobin is already nearly saturated with oxygen (97-98%), leaving little room for improvement through regular breathing. However, oxygen can also dissolve directly into blood plasma, and this is where hyperbaric therapy makes a dramatic difference.

At 3 ATA of pressure while breathing 100% oxygen, the amount of dissolved oxygen in plasma increases approximately 15-fold. This plasma-dissolved oxygen can reach tissues even when blood flow is compromised, making it particularly valuable for treating wounds with poor circulation. The increased oxygen triggers several beneficial responses:

• Angiogenesis: Formation of new blood vessels in oxygen-deprived tissues, improving long-term circulation
• Enhanced white blood cell function: Oxygen-dependent killing mechanisms of neutrophils become more effective against bacteria
• Collagen synthesis: Fibroblasts require adequate oxygen to produce collagen, the building block of wound repair
• Vasoconstriction: Blood vessel narrowing reduces swelling while maintaining oxygenation through dissolved plasma oxygen
• Stem cell mobilization: HBOT stimulates the release of stem cells from bone marrow, contributing to tissue regeneration

What Conditions Can Hyperbaric Oxygen Therapy Treat?

The Undersea and Hyperbaric Medical Society (UHMS) approves HBOT for 14 conditions including decompression sickness, carbon monoxide poisoning, diabetic foot ulcers, radiation tissue injury, gas gangrene, severe anemia, thermal burns, necrotizing infections, osteomyelitis, compromised grafts/flaps, air embolism, crush injuries, sudden hearing loss, and central retinal artery occlusion.

Hyperbaric oxygen therapy has undergone extensive clinical research, resulting in a defined list of approved indications. These conditions have sufficient scientific evidence demonstrating that HBOT provides meaningful clinical benefit beyond standard treatments. The UHMS and European Committee for Hyperbaric Medicine (ECHM) regularly review the evidence and update their recommendations.

It's important to understand that HBOT is not a cure-all treatment. Many conditions marketed for hyperbaric therapy at non-medical facilities lack sufficient evidence of benefit. Seeking treatment at accredited medical facilities ensures you receive evidence-based care for conditions where HBOT has proven effectiveness.

Emergency Conditions

Several life-threatening conditions require urgent hyperbaric oxygen therapy, often as a primary treatment rather than adjunctive therapy. In these emergencies, HBOT can be life-saving when administered promptly.

Decompression sickness (DCS) occurs when dissolved gases, primarily nitrogen, form bubbles in blood and tissues during rapid ascent from diving or high-altitude exposure. Symptoms range from joint pain ("the bends") to neurological damage and death. HBOT works by reducing bubble size through increased pressure and by creating a large diffusion gradient that helps eliminate nitrogen from tissues. Treatment typically begins at 2.8-3 ATA and may require multiple sessions depending on severity.

Carbon monoxide poisoning is another emergency indication where HBOT can be life-saving. Carbon monoxide binds to hemoglobin 200-250 times more strongly than oxygen, effectively blocking oxygen transport to tissues. While breathing 100% oxygen at normal pressure helps, hyperbaric oxygen accelerates CO elimination from the body and may reduce the risk of delayed neurological problems. Studies suggest HBOT should be considered for patients with loss of consciousness, neurological symptoms, or carboxyhemoglobin levels above 25%.

Air or gas embolism occurs when gas bubbles enter the bloodstream and block blood vessels. This can happen during certain medical procedures, diving accidents, or trauma. HBOT reduces bubble size and increases oxygen delivery to tissues downstream of the blockage.

Wound Healing Applications

The most common use of hyperbaric oxygen therapy today is for chronic wound healing, particularly diabetic foot ulcers and radiation-induced tissue damage. These conditions share a common feature: inadequate tissue oxygenation that prevents normal healing processes from occurring.

Diabetic foot ulcers affect approximately 15-25% of people with diabetes during their lifetime. These wounds often fail to heal due to multiple factors including poor circulation, nerve damage, and immune dysfunction. HBOT has been shown in randomized controlled trials to significantly improve healing rates when added to standard wound care. A Cochrane review found that HBOT increases the likelihood of healing by approximately 75-80% compared to standard care alone, and reduces the risk of major amputation.

Radiation tissue damage can occur months or years after radiation therapy for cancer. The radiation damages small blood vessels, leading to chronic tissue hypoxia (low oxygen) that prevents healing. Common manifestations include radiation cystitis (bladder), radiation proctitis (rectum), and osteoradionecrosis (bone death, often in the jaw). HBOT promotes new blood vessel growth in irradiated tissues, restoring oxygen supply and enabling healing. Many patients report significant symptom improvement after 20-40 treatment sessions.

How Should You Prepare for Hyperbaric Oxygen Therapy?

Before HBOT, avoid perfumes, aftershave, cosmetics, lotions, and lip balm as oxygen increases fire risk. Do not bring electronic devices including phones, tablets, or computers into the chamber. Wear cotton clothing provided by the facility, use the restroom beforehand, and bring glucose tablets if you have diabetes.

Proper preparation for hyperbaric oxygen therapy is essential for both safety and treatment effectiveness. The high-oxygen environment inside the chamber creates conditions where certain items could pose fire risks, while other considerations ensure your comfort during the 90-minute session.

The single most important safety consideration is avoiding petroleum-based products and anything that could generate sparks. Oxygen itself is not flammable, but it greatly accelerates combustion of other materials. Items that might seem harmless in everyday life could become dangerous in a hyperbaric chamber. Your treatment center will provide specific instructions, but general guidelines include:

• Cosmetics and personal care products: Avoid perfume, cologne, aftershave, deodorant spray, makeup, nail polish, hair spray, and moisturizing lotions on the day of treatment. Many of these products contain petroleum-based ingredients or alcohol that could pose fire risks.
• Skin care: Do not apply lotions, creams, or lip balm. Petroleum jelly and similar products are particularly concerning. If you have dry skin, ask your treatment center about approved alternatives.
• Electronic devices: Mobile phones, tablets, laptops, and electronic games cannot enter the chamber. Batteries can pose both fire and off-gassing risks in the hyperbaric environment.
• Clothing: You will change into cotton clothing or scrubs provided by the facility. Your own cotton underwear is typically permitted. Avoid synthetic fabrics which can generate static electricity.

Medical Considerations Before Treatment

Several medical conditions require special attention or may affect your eligibility for hyperbaric oxygen therapy. During your initial evaluation, the hyperbaric medicine team will review your complete medical history and current medications.

If you have diabetes, bring glucose tablets or another fast-acting sugar source into the chamber. Hyperbaric oxygen therapy can lower blood sugar levels, and you cannot easily exit the chamber once treatment begins. Some facilities check blood glucose before and after each session.

Ear and sinus conditions may affect your ability to equalize pressure during treatment. If you have a cold, sinus infection, or ear infection, your treatment may need to be postponed. Patients with permanent ear tubes can usually receive HBOT without problems.

Certain medications interact with hyperbaric oxygen therapy. Chemotherapy drugs like doxorubicin (Adriamycin), bleomycin, and cisplatin may have increased toxicity under hyperbaric conditions. Other medications including disulfiram (Antabuse) and mafenide acetate (Sulfamylon) are typically contraindicated. Always provide a complete medication list to your treatment team.

What Happens During a Hyperbaric Oxygen Therapy Session?

During HBOT, you enter a pressurized chamber, receive an oxygen mask, and experience gradual pressure increase (feeling warmth and ear pressure). The main treatment phase lasts 60-90 minutes at full pressure while breathing pure oxygen. Staff monitor you via camera and intercom throughout. The session ends with gradual decompression back to normal pressure.

Understanding what happens during a hyperbaric oxygen therapy session can help reduce anxiety and ensure you're prepared for the experience. The process follows a standardized protocol designed for both safety and treatment effectiveness.

Entering the Chamber

When you arrive for your appointment, you'll first change into the cotton clothing or scrubs provided by the facility. Staff will check that you haven't brought any prohibited items and may have you walk through a safety checklist. If you have any new symptoms or concerns since your last visit, this is the time to mention them.

You'll then enter the hyperbaric chamber. In a monoplace chamber (designed for one person), you typically lie on a stretcher-like bed that slides into a clear cylindrical tube. Multiplace chambers are larger rooms where several patients can be treated simultaneously, usually sitting in chairs. In multiplace chambers, you'll breathe oxygen through a mask or hood while the chamber itself is pressurized with air.

The chamber has communication systems allowing you to speak with staff throughout the treatment. In monoplace chambers, you may have a microphone and speaker system. Multiplace chambers usually have an attendant inside who can assist patients directly.

The Compression Phase

Once the chamber is sealed, pressurization begins gradually. This phase typically takes 10-15 minutes and is often compared to the feeling of descending in an airplane or diving underwater. As pressure increases, you'll notice several sensations:

Ear pressure is the most common sensation. As external pressure increases, the air behind your eardrum must equalize to prevent discomfort. You can equalize by swallowing, yawning, or using the Valsalva maneuver (gently blowing while pinching your nose shut). Staff will guide you through this process and can slow the compression rate if you have difficulty.

Warmth occurs because compressing gas generates heat (a basic principle of thermodynamics). The chamber may feel warm for several minutes until the temperature stabilizes. This is completely normal and the temperature will return to a comfortable level once full pressure is reached.

If you experience significant discomfort during compression that doesn't resolve with ear-clearing techniques, alert the staff immediately. They can stop or slow the pressurization process. Never suffer in silence - unresolved pressure can cause ear injury.

The Treatment Phase

Once the chamber reaches the prescribed pressure (typically 2.0-2.4 ATA for most wound healing applications), the main treatment phase begins. You'll breathe pure oxygen through a mask, hood, or the chamber atmosphere itself for 60-90 minutes, depending on your treatment protocol.

During this phase, you can relax, read, listen to music (if available), or simply rest. Many patients actually fall asleep during treatment. Staff monitor you continuously through windows and cameras, so you're never truly alone even though it may feel that way.

Most treatment protocols include brief "air breaks" - periods of 5-10 minutes where you breathe regular air instead of pure oxygen. These breaks reduce the risk of oxygen toxicity, particularly to the lungs. The total oxygen breathing time varies by protocol but is typically 60-90 minutes per session.

The Decompression Phase

At the end of the treatment phase, the pressure gradually decreases back to normal atmospheric levels. This decompression typically takes 10-15 minutes and is generally more comfortable than compression. You may notice your ears "popping" as pressure equalizes, similar to ascending in an airplane.

Once the chamber reaches normal pressure, the door opens and you can exit. Most people feel completely normal after treatment and can drive themselves home and return to normal activities immediately.

What Are the Risks and Side Effects of HBOT?

Common HBOT side effects include temporary ear pressure and popping (like airplane pressure), mild fatigue, temporary nearsightedness that resolves within weeks, and claustrophobia in enclosed chambers. Rare serious risks include oxygen toxicity seizures (less than 0.01% of treatments), barotrauma to ears/sinuses, and pulmonary oxygen toxicity with extended treatment.

Hyperbaric oxygen therapy is generally considered safe when performed at accredited medical facilities under proper supervision. However, like any medical treatment, it carries certain risks and side effects that patients should understand before beginning therapy.

Common Side Effects

Middle ear barotrauma is the most common complication, occurring in approximately 2% of patients. This results from difficulty equalizing pressure in the middle ear and can range from mild discomfort to more significant injury. Symptoms include ear pain, muffled hearing, and occasionally bleeding from the ear. Most cases resolve with conservative treatment, and techniques like using decongestants before treatment or slowing the compression rate can help prevent occurrence.

Sinus pressure and pain can occur if sinuses don't equalize properly during pressure changes. Patients with active sinus infections or congestion are at higher risk. Treatment is usually postponed if you have significant nasal congestion.

Temporary vision changes affect many patients who undergo extended HBOT treatment courses. The increased oxygen causes temporary changes in the lens of the eye, typically resulting in mild nearsightedness (myopia). This usually develops after 20-30 treatments and resolves completely within 2-8 weeks after completing therapy. If you need new glasses, it's advisable to wait until several weeks after finishing HBOT.

Fatigue is commonly reported after treatment sessions, though many patients feel energized. The response varies individually and may change throughout a treatment course.

Rare but Serious Risks

Oxygen toxicity seizures occur very rarely - in less than 1 in 10,000 treatments at standard pressures and durations. The risk increases at higher pressures and longer treatment times. Seizures caused by oxygen toxicity stop when oxygen concentration is reduced and typically don't cause lasting harm. Air breaks during treatment are specifically designed to minimize this risk.

Pulmonary oxygen toxicity (lung damage from prolonged oxygen exposure) is primarily a concern with extended treatment protocols. Standard HBOT courses for wound healing rarely cause significant pulmonary issues. Patients undergoing intensive treatment for conditions like decompression sickness are monitored carefully.

How Effective Is Hyperbaric Oxygen Therapy?

HBOT effectiveness varies by condition: decompression sickness shows near 100% response when treated promptly; diabetic foot ulcers show 75-80% improved healing rates compared to standard care; radiation tissue damage shows significant symptom improvement in 70-90% of patients after 30-40 sessions. Evidence is strongest for UHMS-approved indications.

The effectiveness of hyperbaric oxygen therapy depends significantly on the condition being treated, the timing of treatment, and patient-specific factors. Understanding the evidence for different indications helps set realistic expectations.

For decompression sickness, HBOT is the definitive treatment with near-universal effectiveness when administered promptly. Delayed treatment reduces but doesn't eliminate benefit. The U.S. Navy treatment tables have been refined over decades and provide standardized protocols based on symptom severity.

For diabetic foot ulcers, multiple randomized controlled trials and systematic reviews demonstrate significant benefit. The Cochrane Database of Systematic Reviews found that HBOT significantly increases the chance of healing and reduces the risk of major amputation. A typical course of 20-40 treatments results in complete healing in approximately 75-80% of previously non-healing wounds. However, HBOT works best as part of comprehensive wound care including infection control, off-loading pressure, and blood sugar management.

For radiation tissue damage, evidence comes primarily from case series and observational studies, with some randomized trials for specific conditions. Response rates vary by affected tissue: radiation cystitis and proctitis often show dramatic symptom improvement, while osteoradionecrosis of the jaw shows good results when HBOT is combined with surgery. Most patients require 30-40 treatments to see meaningful improvement.

Conditions with Limited or No Proven Benefit

Many conditions are marketed for hyperbaric therapy at non-medical facilities without adequate scientific evidence. It's important to distinguish between UHMS-approved indications and unproven uses:

Autism spectrum disorder has been studied in several trials, with a Cochrane review concluding there is no evidence of benefit from HBOT. Despite marketing claims, parents should be cautious about pursuing this unproven treatment.

Cerebral palsy similarly lacks evidence of benefit from controlled trials. Some studies showed improvements in both treated and control groups, suggesting placebo effects or natural variation rather than true treatment effect.

Anti-aging and wellness applications promoted by some facilities lack scientific support. While cellular effects of HBOT are well-documented, translating these into meaningful health benefits for healthy individuals has not been demonstrated.

Athletic recovery and performance enhancement is another popular but unproven application. While some athletes use hyperbaric chambers, controlled studies have not shown significant benefits for recovery or performance in healthy individuals.

What Should You Know About HBOT Aftercare?

After HBOT, most people feel normal and can resume daily activities immediately. Some experience mild fatigue or temporary vision changes after multiple sessions. Continue any prescribed wound care between treatments. Report new symptoms to your treatment team. For ongoing courses, sessions are typically scheduled daily (5 days/week) for optimal results.

One of the advantages of hyperbaric oxygen therapy is minimal post-treatment restrictions. Unlike many medical procedures, HBOT doesn't require extended recovery time, and most patients can return to normal activities immediately after each session.

You can drive yourself home after treatment unless you've been advised otherwise due to specific medical conditions. Most patients feel normal, though some experience mild fatigue or a sense of relaxation similar to after a nap. Drinking water after treatment may help if you feel slightly dehydrated.

If you're receiving HBOT for wound healing, continue all other aspects of your wound care plan between treatments. This includes keeping wounds clean, changing dressings as directed, using offloading devices if prescribed, and managing blood sugar if you have diabetes. HBOT works best as part of comprehensive care, not as a replacement for standard treatments.

For most conditions requiring multiple treatments, sessions are scheduled daily, typically five days per week. This intensive schedule provides optimal oxygen delivery for tissue healing. Missing sessions can slow progress, so it's important to plan your schedule around treatment when starting an HBOT course.