Hyperbaric Oxygen Therapy

What is Hyperbaric Oxygen Therapy?

Hyperbaric Oxygen Therapy (HBOT) is a medically supervised treatment that delivers 100% oxygen in a pressurized chamber, typically at 1.5 to 3 times normal atmospheric pressure (ATA). This pressurized environment allows oxygen to dissolve directly into the plasma in concentrations far greater than what hemoglobin alone can carry, dramatically increasing oxygen availability to the body’s tissues, especially those affected by poor circulation, injury, or inflammation. HBOT is utilized in both acute and chronic settings to support healing, reduce inflammation, improve tissue oxygenation, and enhance neurological and immune function. It is FDA-approved for 14 conditions and is being increasingly studied for its role in neurorehabilitation, immune recovery, and the management of long COVID.

Types of Hyperbaric Chambers

There are two main types of hyperbaric chambers used in clinical and wellness settings, each differing in capacity, construction, pressure level, and intended use.

Monoplace chambers are designed for a single patient at a time and are typically made from transparent acrylic. These chambers are filled with 100% oxygen and pressurized to therapeutic levels ranging from 1.5 to 3.0 ATA. Because of their personalized environment and patient visibility, monoplace chambers are commonly used in outpatient clinics to treat chronic wounds, post-radiation injuries, and carbon monoxide poisoning. The controlled environment minimizes the risk of contamination, allowing the patient to lie comfortably while breathing pure oxygen.

Multiplace chambers are larger, hospital-grade steel vessels that can accommodate multiple patients simultaneously. Inside these chambers, the environment is pressurized with ambient air, while each patient receives oxygen through a mask, hood, or endotracheal tube. Multiplace chambers are typically found in trauma centers and hospitals where intensive medical care and constant monitoring are required. Their size and staffing allow clinicians to manage critically ill patients, making them ideal for treating conditions like gas embolism or decompression sickness.

Benefits of Hyperbaric Oxygen Therapy

The therapeutic effects of Hyperbaric Oxygen Therapy are derived from its ability to supersaturate the body with oxygen. This triggers a range of biological responses that support healing, regeneration, and immune resilience. Below are some well-documented clinical and physiological benefits:

Stimulates New Blood Vessel Growth (Angiogenesis)

HBOT significantly increases oxygen tension in tissues, which promotes the development of new blood vessels, particularly in hypoxic or injured areas. The elevated oxygen levels stimulate the release of vascular endothelial growth factor (VEGF), enhancing capillary formation and microcirculation. According to a study by StatPearls, HBOT has demonstrated effectiveness in improving wound healing by increasing transcutaneous oxygen tension (TcPO₂) and promoting angiogenesis in non-healing wounds and irradiated tissues.

Accelerates Wound Healing and Tissue Repair

Oxygen is essential for the function of fibroblasts, collagen production, and epithelial repair. HBOT increases oxygen delivery to damaged tissues, supporting cellular metabolism and the structural rebuilding of the extracellular matrix. A study published in Semantic Scholar reported that diabetic wounds treated with HBOT had significantly faster healing rates due to enhanced collagen deposition and better oxygenation of the wound site.

Mobilizes Stem Cells for Regeneration

HBOT stimulates the release of stem and progenitor cells from the bone marrow into the circulation. These cells play a crucial role in tissue regeneration and immune modulation. In a landmark clinical study, Dr. Stephen Thom and colleagues found that a single HBOT session doubled circulating CD34+ stem cells, and 20 sessions increased levels eightfold, demonstrating a nitric oxide–dependent regenerative response. Follow-up studies supported its role in vascular repair and post-injury recovery.

Enhances Immune Function and Fights Infection

Hyperbaric oxygen therapy strengthens the body’s immune defenses by enhancing white blood cell activity, particularly neutrophil function. It supports oxygen-dependent intracellular killing of pathogens and reduces inflammation by inhibiting the production of pro-inflammatory cytokines. HBOT also enhances the efficacy of antibiotics, particularly against anaerobic bacteria in infections such as osteomyelitis and necrotizing fasciitis. StatPearls highlights HBOT as a vital adjunctive therapy in combating severe infections, especially in ischemic tissues where standard treatments fall short.

Reduces Inflammation and Edema

Hyperbaric Oxygen Therapy helps to significantly alleviate tissue swelling and reduce inflammation, which are common barriers to healing in conditions such as crush injuries, compartment syndrome, burns, and ischemic wounds. At increased oxygen pressures, HBOT promotes vasoconstriction and improves microcirculatory blood flow, thereby decreasing capillary leakage and removing excess interstitial fluid. A comprehensive review in StatPearls explains that HBOT-induced vasoconstriction reduces vasogenic edema and inflammation in both soft tissues and the brain, helping to restore physiological redox balance in ischemic regions. 

In addition, a systematic review and meta-analysis published in the International Journal of Molecular Sciences found that HBOT lowered levels of inflammatory markers, such as interleukin-1β and tumor necrosis factor-alpha (TNF-α), while enhancing antioxidant enzyme activity in patients with chronic wounds. This dual action, which reduces swelling and modulates cytokine activity, supports faster recovery in both acute and chronic injury settings.

Provides Neuroprotection and Cognitive Support

Hyperbaric Oxygen Therapy (HBOT) offers compelling neuroprotective benefits by increasing oxygen delivery to the brain, enhancing neuroplasticity, and stimulating the release of neurotrophic factors critical for cellular repair. These effects have been particularly valuable in patients recovering from stroke, traumatic brain injury (TBI), and age-related cognitive decline.

A landmark randomized controlled trial published in PLOS ONE demonstrated that stroke patients who received 40 HBOT sessions, even up to three years after the stroke, experienced significant improvements in cognitive performance, motor function, and quality of life. Brain imaging using SPECT scans showed increased blood flow and metabolic activity in areas previously considered non-functional, supporting the concept that HBOT may promote true neuroregeneration.

Improves Symptoms of Long COVID and Fatigue Syndromes

Recent studies have shown that HBOT can significantly reduce symptoms associated with long COVID, including fatigue, shortness of breath, cognitive dysfunction, and muscle pain. A double-blind, randomized controlled trial published in Scientific Reports found that HBOT improved physical and mental performance among long COVID patients, with sustained benefits seen after multiple treatments.

Possible Side Effects and Contraindications

Hyperbaric Oxygen Therapy (HBOT) is generally safe when administered in a controlled medical environment, but like any medical intervention, it carries potential side effects and contraindications. Most adverse effects are mild and temporary, while more serious complications are rare and typically avoidable with proper screening and monitoring.

Possible Side Effects

  • Ear and Sinus Barotrauma – One of the most frequent side effects is the ear or sinus barotrauma, which occurs due to pressure changes during compression and decompression. Patients may experience ear pain, a sensation of fullness, or temporary changes in hearing. This is typically preventable by teaching patients how to equalize pressure effectively, much like when flying in an airplane.
  • Temporary Vision Changes – Some individuals may develop temporary nearsightedness (myopia) after repeated HBOT sessions. This occurs due to changes in the shape of the lens resulting from prolonged exposure to high-pressure oxygen. The effect is reversible and typically resolves within a few weeks after therapy ends.
  • Fatigue or Lightheadedness – Some patients may report mild fatigue, dizziness, or a sensation of lightheadedness following a session. These symptoms are usually short-lived and resolve without the need for medical intervention.
  • Oxygen Toxicity (Central Nervous System) – Although rare, breathing 100% oxygen at high pressure for extended periods can lead to central nervous system oxygen toxicity, most commonly manifesting as a seizure. This is a well-studied risk that can be mitigated through careful management of treatment pressure and duration. If a seizure does occur, it is typically brief and fully reversible.
  • Pulmonary Barotrauma (Very Rare) – In extremely rare cases, particularly among patients with underlying lung disease or air-trapping disorders, pulmonary barotrauma may occur. This involves injury to the lungs due to pressure changes and can result in conditions like pneumothorax (collapsed lung) if not properly managed.

Precautions and Contraindications

  • Chronic Obstructive Pulmonary Disease (COPD) with Air Trapping – Patients with COPD, especially those with emphysematous bullae, are at risk of lung over-expansion and rupture under pressure. Pulmonary evaluation is essential before initiating therapy.
  • High Fever or Active Upper Respiratory Infection – These conditions may impair the patient’s ability to equalize middle ear pressure, thereby increasing the likelihood of barotrauma. Treatment should be postponed until the illness resolves.
  • Uncontrolled Seizure Disorders – Although HBOT is not inherently epileptogenic, oxygen may lower the seizure threshold in susceptible individuals. Patients with poorly controlled epilepsy should be closely monitored.
  • Severe Claustrophobia – Individuals with claustrophobia may experience significant anxiety when placed inside a sealed chamber. In many cases, supportive care or mild sedation can help manage this condition effectively.
  • Pregnancy (Non-Emergent Cases) – While HBOT is considered safe in emergencies like carbon monoxide poisoning, its use during pregnancy for elective or non-emergent conditions should be approached cautiously and evaluated on a case-by-case basis.
  • Recent Ear or Sinus Surgery – Patients who have recently undergone surgical procedures involving the ear or sinuses are at increased risk of pressure-related injury and should defer HBOT until healing is complete.
  • Untreated Pneumothorax (Collapsed Lung) – HBOT is strictly contraindicated in individuals with an untreated pneumothorax because the increased pressure can cause the trapped air to expand, worsening the condition and potentially leading to a life-threatening situation.
  • Concurrent Use of Certain Chemotherapy Agents – Chemotherapy drugs such as doxorubicin, cisplatin, and bleomycin may interact adversely with hyperbaric oxygen, increasing the risk of tissue damage. Patients on these medications should not undergo HBOT unless under strict oncologic supervision.

Keep in Mind

All patients undergoing HBOT should receive a comprehensive medical evaluation to assess eligibility and minimize risks. Treatment protocols adhere to safety standards established by the Undersea and Hyperbaric Medical Society (UHMS) and are tailored to each individual’s condition, comorbidities, and therapeutic objectives. With proper oversight, HBOT remains a low-risk and highly effective treatment for a wide range of medical conditions.

Summary

Hyperbaric Oxygen Therapy offers a highly effective, non-invasive method of delivering oxygen to the body in concentrations far exceeding those allowed by normal respiration. It addresses one of the most fundamental drivers of chronic disease: tissue-level oxygen deficiency. By improving oxygen availability, enhancing circulation, reducing inflammation, stimulating tissue regeneration, and strengthening immune defenses, HBOT supports healing across multiple bodily systems. Whether used as a primary treatment or adjunct to existing medical care, HBOT represents a scientifically sound and clinically versatile solution in the field of integrative and functional medicine.

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