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Hyperbaric Oxygen: A Spectrum of Emerging Treatments

The views expressed are those of the author and are not necessarily those of Scientific American.

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By Nathalie Sami and Janice Wong

The hyperbaric chamber on Catalina Island at the USC Wrigley Marine Institute.

The hyperbaric chamber on Catalina Island at the USC Wrigley Marine Institute.

Certified scuba divers are familiar with the use of hyperbaric oxygen therapy (HBOT) for decompression sickness treatment. However, in the past 50 years, researchers have revealed HBOT’s broad applications to human physiology and medicine. The outlook for HBOT applications for treating wounds, neurological diseases, and even certain cancers appears promising. What once seemed relevant only for scuba divers has now been discovered to benefit members of the general population.


HBOT involves the administration of pure, 100% oxygen in a compression chamber at pressures above atmospheric levels. The resultant increase of oxygen content in blood yields a broad variety of physiological effects, because increased pressure allows oxygen to saturate more effectively in the body. For scuba divers, this increased oxygen pressure reduces the volume of inert-gas bubbles in blood vessels, reversing air embolism or decompression sickness (Danesh-Sani et al. 2012). Moreover, researchers have described several beneficial influences of HBOT on healing damaged tissues: increased white blood cell activity, reduced swelling, healing time reduction, tissue regeneration, and even synergistic activity with antibiotics (Strużyna et al. 2008). The Undersea Hyperbaric Medicine Society recommends many applications for HBOT that have proven successful (Table 1). Beyond these now standard uses, several novel research areas demonstrate further beneficial HBOT applications. HBOT applications to wounds, cancers, and neurological and vascular diseases will be discussed below.

Table 1

Table 1


Low oxygen content caused by swelling or burns reduces PH and prohibits wound healing. On the other hand, higher oxygen tension improves healing of wounds by stimulating tissue-forming cells (Danesh-Sani et al. 2012). Hyperbaric oxygenation of wounds thus initiates wound-healing events such as tissue and cell generation and resistance to infection (Shah 2010). Furthermore, oxygen helps fight against infections by killing bacteria that cannot tolerate oxygen (Youn 2001). For example, in treating injuries as common as burns, HBOT reduces healing time and number of infections (Strużyna et al. 2008).

Cholesterol Crystal Embolism (CCE)

(A) Physical lesion at presentation; (B) worsening of lesions after 1 month of treatment; and (C) complete resolution of necrotic lesions after 1 month of HBOT (Gurgo et al., 2011).

(A) Physical lesion at presentation; (B) worsening of lesions after 1 month of treatment; and (C) complete resolution of necrotic lesions after 1 month of HBOT (Gurgo et al., 2011).

Such benefits also apply to patients of cholesterol crystal embolism (CCE), a disease with a high mortality rate. In a case study of a 56-year-old man who developed CCE and who had already undergone an unsuccessful standard treatment, HBOT caused rapid improvement. As seen in Fig. 1, after two months, complete recovery was obtained, leading the authors to conclude that HBOT may serve as an effective treatment in CCE (Gurgo et al., 2011).

Bone Healing

Another known application for HBOT is with bone healing, during which HBOT increases white blood cell activity and tissue formation (Danesh-Sani et al. 2012). Also, HBOT may induce the formation of new blood vessels by stimulating an increase of stem cells within the tissues (Shah 2010). An application of bone-healing effects regards the influence of HBOT on bone tissue after the cessation of smoking. Smoking has proven to delay bone healing and impair blood circulation; however, HBOT mitigates the effects of smoking on bone healing, now proving that bone damage caused by smoking may be reversible (Yen et al. 2008).


Surgical injuries present yet another opportunity for HBOT intervention. Danesh-Sani and colleagues (2012) asserted that use of HBOT before surgical treatment significantly reduces risk of postoperative infection and accelerates healing, and other studies demonstrate benefits of post-operative HBOT application. In the case of urethral reconstructive operations, which commonly cause decreased erectile function, findings suggest that HBOT stimulates the regeneration of injured nerves and promotes tissue formation to allow erectile function recovery (Yuan et al. 2011).


Solid tumors, which are often hypoxic, can increase genetic instability and activate invasive growth to exacerbate certain types of cancer (Moen & Stuhr 2012). By providing oxygenation, HBOT induces excessive oxygenation, which causes rapid degeneration and tumor cell destruction. As a result, HBOT is thought to yield beneficial effects in several types of tumors with minimal invasiveness (Danesh-Sani et al. 2012). As well, HBOT could improve and help overcome chemotherapeutic resistance by increasing cellular sensitivity to radiotherapy (Moen & Stuhr 2012).

Breast and Prostate Cancer

The adjunctive use of HBOT with chemotherapy has shown positive effects on reducing breast cancer. As the most frequently occurring cancer in women, breast cancer provides a worldwide threat, and HBOT has shown a strong effect against different mammary cancer cells. HBOT has also led to less aggressive and restricted growth of large tumor cell colonies (Moen & Stuhr 2012). Successful experiments regarding prostate cancer cells with HBOT have also generated affirming results. Cancer of the prostate is the second leading type of cancer for men, and in vitro experiments have demonstrated the efficacy of HBOT in decreasing the cancer cells’ growth rate and increasing their sensitivity to chemotherapy (Moen & Stuhr 2012).

Neurological Diseases

The success of recent studies regarding the use of HBOT in improving neuromuscular pathologies has merited further investigation to confirm its beneficial uses and mechanisms.

The most evidence-supported neurological application for HBOT lies with autism spectrum disorders (ASD), which is currently diagnosed in 1 in 88 children in the US (CDC 2012). ASD includes neurodevelopmental disorders characterized by restrictive and repetitive behaviors as well as impairments in communication and social interaction. Several experiments involving the effects of HBOT on children with autism have reported clinical improvements, citing decreased inflammation and improved blood circulation to the brain. One study resulted in improvements in overall functioning for 80% of autistic children treated with HBOT, leading to the conclusion that HBOT is a safe treatment for as prevalent a neurological disease as ASD (Rossignol et al. 2009).

Vascular Diseases

HBOT may reduce the symptoms of vascular diseases by improving circulation and oxygenation.

Vascular Dementia

For instance, vascular dementia, caused by decrease blood flow to the brain, is characterized by loss of memory, confusion, problems with speech and understanding, and an increased dependence on others. While no effective treatment has been established, models have demonstrated HBOT’s ability to improve blood supply and promote nerve tissue formation in the brain and enhance learning and memory. One study found that patients receiving HBOT exhibited better cognitive function than patients of the control group after 12 weeks of treatment (Xiao et al. 2012).

Carbon Monoxide Poisoning

HBOT is also used to treat carbon monoxide poisoning. Usually, hemoglobin proteins in red blood cells transport oxygen. However, carbon monoxide binds more readily to hemoglobin than oxygen.  As a result, the body is unable to distribute oxygen throughout the body when exposed to carbon monoxide resulting in hypoxia (Mills and Saulsberry, 2011). HBOT is effectively used to reverse this harmful effect.

Arterial gas embolisms and stroke

One of the common uses of HBOT is to treat arterial gas embolisms. An arterial gas embolism is when that gas in the circulatory system goes through arteries or pulmonary veins and blocks blood flow (Muth and Shank, 2000). In non-diving accidents the cause of arterial gas embolisms are caused by medical mistakes such as accidentally injecting air in patients. These escaped bubbles are very dangerous because they block blood flow to certain areas, resulting in hypoxic tissue. In the brain, reduced blood and oxygen flow can cause a stroke and brain damage. Acute stroke results from impairment of blood flow to the brain, which causes neuron cell death. HBOT may increase available oxygen and reduce brain swelling to prevent further neuron damage (Bennett et al. 2010). Stroke is a leading cause of death in the US, so these discoveries may yield huge implications. Hyperbaric medicine is effective in treating these problems because raising the pressure of the chamber causes the size of gas bubbles to decrease (Bell and Gill, 2004). In addition to the reduction in bubble size, oxygen can more easily dissolve to benefit the previously hypoxic environment (Muth and Shank, 2000).

Insulin Sensitivity

Another study proved that HBOT creates a substantial increase in insulin sensitivity. The improvement occurs rapidly (e.g., within three treatments) and is sustained at least until the thirtieth treatment. HBOT may induce insulin sensitivity by oxygenating fat tissue and reducing inflammation (Wilkinson et al. 2012). This discovery could have important implications, because insulin insensitivity is associated with diabetes, high blood pressure, heart disease, obesity, and certain types of cancer, which cause the majority of deaths in America (Colberg 2008).


While HBOT provides many beneficial treatments, there are some associated risks, such as oxygen toxicity. Metabolizing oxygen releases highly reactive byproducts that build up over time and saturate in tissue with increasing pressure. Resulting oxygen toxicity can lead to respiratory issues and seizures, because the toxicity often affects the lungs and central nervous system (Almeling et al. 2000).  Another risk commonly associated with HBOT is barotraumatic lesions, the result of unequal pressure between the outside and inside of an air containing space. For humans, the middle ear most commonly experiences barotrauma, but other areas include lungs, nasal cavities and sinuses, inner ears, and teeth (Almeling et al, 2000). Equalizing during treatment is important, because people who are unable to equalize their ears during HBOT can experience middle ear barotrauma (Undersea and Hyperbaric Medical Society, 2011). Middle ear barotrauma, the most common side effect of HBOT, occurs when the pressure outside the ear is greater than the pressure of the middle ear.


While there are some risks associated with hyperbaric treatment, careful administration and thorough monitoring can limit the risk of side effects of HBOT. Although HBOT has not yet been adopted as the primary treatment for many of the mentioned conditions, it provides a minimally-invasive opportunity for treatment. The discovery of HBOT’s physiological benefits has demonstrated implications for treating the most prevalent ailments in the US. Thus, the newly-proposed, broadly-reaching benefits of HBOT applications beyond diving injury treatment merit deeper investigations. Indeed, with so many potential treatment functions, HBOT has earned its reputation as “a therapy in search of diseases” (Danesh-Sani et al. 2012).


Almeling M, Busch R, Peters P, Plafki C (2000) Complications and side effects of hyperbaric oxygen therapy. Aviation, Space, and Environmental Medicine 71(2): 119-24

Autism Spectrum Disorders (ASD) (2012). Centers for Disease Control and Prevention. Retrieved from

Bennett, M. H., Wasiak, J., Schnabel, A., Kranke, P., & French, C. (2010). Hyperbaric oxygen therapy for acute ischemic stroke. Stroke, 41(4), e185-e186. doi: 10.1161/STROKEAHA.109.571380

Colberg, S. (2008). Increasing insulin sensitivity. Retrieved from

Bell CAN, Gill AL (2004) Hyperbaric oxygen: its uses, mechanisms of action and outcome. QJM: An International Journal of Medicine 97(7): 385-395

Danesh-Sani, S. A., Shariati-Sarabi, Z., & Feiz, M. R. (2012). Comprehensive review of hyperbaric oxygen therapy. The Journal of Craniofacial Surgery, 23(5), e483-e491. doi: 10.1097/SCS.0b013e3182668777

Gurgo, A., Volpe, M., Valenti, V., Paneni, F., Passerini, J., Di Vavo, M., . . . Sabani, A. (2011). Hyperbaric oxygen therapy in a case of cholesterol crystal embolization. The American Journal of Emergency Medicine. ( No. 29). doi: 10.1016/j.ajem.2010.05.023

Mills R, Saulsberry AJ (2011) Diseases and Conditions. Hyperbaric Link. Retrieved from

Moen, I., & Stuhr, L. E. B. (2012). Hyperbaric oxygen therapy and cancer–a review. Targeted Oncology, 7(4), 233-242. doi: 10.1007/s11523-012-0233-x

Muth CM, Shank ES (2000) Gas Embolism. New England Journal of Medicine 342: 476-482

Rossignol, D. A., Grushkin, B., Mumper, E. A., Rossignol, L. W., Smith, S., Schneider, C., . . . Hintz, G. (2009). Hyperbaric treatment for children with autism: A multicenter, randomized, double-blind, controlled trial. BMC Pediatrics, 9(1), 21-21. doi: 10.1186/1471-2431-9-21

Shah, J. (2010). Hyperbaric oxygen therapy. The Journal of the American College of Certified Wound Specialists, 2(1), 9-13. doi: 10.1016/j.jcws.2010.04.001

Wilkinson, D., Chapman, I. M., & Heilbronn, L. K. (2012). Hyperbaric oxygen therapy improves peripheral insulin sensitivity in humans. Diabetic Medicine : A Journal of the British Diabetic Association, 29(8), 986-989. doi: 10.1111/j.1464-5491.2012.03587.x

Xiao, Y., Wang, J., Jiang, S., & Luo, H. (2012). Hyperbaric oxygen therapy for vascular dementia. Cochrane Database of Systematic Reviews (Online). doi: 10.1002/14651858.CD009425.pub2

Yen, C., Tu, Y., Ma, C., Yeh, J., Kao, F., Yu, S., Ueng, S. W. (2008). Measurement of tibial endothelial cell function after cigarette smoking, cessation of smoking and hyperbaric oxygen therapy. Injury, 39, 40-46. doi: 10.1016/j.injury.2008.08.030

Yuan, J., Yang, L., Wang, Y., Ding, T., Chen, T., & Lu, Q. (2011). Hyperbaric oxygen therapy for recovery of erectile function after posterior urethral reconstruction. International Urology and Nephrology, 43(3), 755-761. doi: 10.1007/s11255-010-9870-0

Youn BA (2001) Oxygen and its Role in Wound Healing. Natural Health Information Archive. Retrieved from

The authors, Nathalie Sami (left) and Janice Wong (right), in front of the Catalina Hyperbaric Chamber on USC Wrigley Marine Institute Campus.

The authors, Nathalie Sami (left) and Janice Wong (right), in front of the Catalina Hyperbaric Chamber on USC Wrigley Marine Institute Campus.

About the authors:

Nathalie Sami is a rising sophomore majoring in Environmental Science and Health in the USC Dana and Dornsife College of Letters, Arts, and Sciences. Her interests include playing, coaching and watching basketball, learning about sustainable lifestyles, and volunteering at health sites.

Janice Wong is an incoming sophomore majoring in environmental science and health at the USC Dana and David Dornsife College of Letters, Arts and Sciences.

Editor’s note: Scientific Research Diving at USC Dornsife is offered as part of an experiential summer program offered to undergraduate students of the USC Dana and David Dornsife College of Letters, Arts and Sciences through the Environmental Studies Program.  This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island and throughout Micronesia. Students investigate important environmental issues such as ecologically sustainable development, fisheries management, protected-area planning and assessment, and human health issues. During the course of the program, the student team will dive and collect data to support conservation and management strategies to protect the fragile coral reefs of Guam and Palau in Micronesia.

Instructors for the course include Jim Haw, Director of the Environmental Studies Program in USC Dornsife, Assistant Professor of Environmental Studies David Ginsburg, Lecturer Kristen Weiss, SCUBA instructor and volunteer in the USC Scientific Diving Program Tom Carr and USC Dive Safety Officer Gerry Smith of the USC Wrigley Institute for Environmental Studies

Previously in this series:

The 2013 Guam and Palau Expedition Begins
A New Faculty Member on the Team
An Analysis of Sargassum Horneri Ecosystem Impact
Marine Protected Areas and Catalina Island: Conserve, Maintain and Enrich
Northern Elephant Seals: Increasing Population, Decreasing Biodiversity
The Relationship Between the Economy and Tourism on Catalina Island
Guam and Palau 2013: New Recruits and New Experiences
Bringing War to the “Island of Peace” – The Fight for the Preservation of Jeju-do
Dreading the Dredging: Military Buildup on Guam and Implications for Marine Biodiversity in Apra Harbor
Is the Commonwealth of the Northern Mariana Islands Doing Enough?
The Status of Fisheries in China: How deep will we have to dive to find the truth?
The Philippines and Spratly Islands: A Losing Battle
The Effects of Climate Change on Coral Reef Health
The Senkaku/Diaoyu Island Dispute in the East China Sea
The UNESCO World Heritage Site Selection Process
Before and After the Storm: The Impacts of Typhoon Bopha on Palauan Reefs
An interconnected environment and economy- Shark tourism in Palau
A Persistent Case of Diabetes Mellitus in Guam
Homo Denisova and Homo Floresiensis in Asia and the South Pacific
Investigating the Effectiveness of Marine Protected Areas in Mexico Using Actam Chuleb as a Primary Example
Okinawa and the U.S. military, post 1945
Offshore Energy Acquisition in the Western Pacific: The Decline of the World’s Most Abundant Fisheries
Military Buildup’s Environmental Takedown
Challenges Facing Japan’s Marine Fisheries

About the Author: Dr. Jim Haw is Ray R. Irani Professor of Chemistry and director of the Environmental Studies Program in the USC Dana and Dornsife College of Letters, Arts and Sciences. He is also a scientific, technical and recreational diver.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. ironjustice 12:41 pm 06/28/2013

    Hypoxia causes increased red blood cells. Oxygenation results in fewer red blood cells , no longer needed because of the increased oxygen. Any disease which manifests increased red blood cells will benefit from increased oxygen in the blood. Hypervolemia for example.
    “he major finding was a 39% death rate in patients that
    were hypervolemic (excess blood volume) vs. 0% death rate for those who were normovolemic/hypovolemic (normal blood volume/mildly reduced blood volume). For those hypervolemic patients that were followed for a median duration of 719 days, the death rate was almost 55% vs. 0% for those patients who were normovolemic to slightly hypovolemic.”

    Link to this
  2. 2. CharlieinNeedham 11:27 pm 07/1/2013

    There may be a very few instances where hyperbaric oxygen therapy is useful.

    Very few.

    But the technology is very expensive.

    To recoup the investment, it is very tempting to stretch the indications for its use.

    Very tempting.

    To paraphrase Eisenhower: Beware the medical-industrial complex.

    [The reason hyperbaric oxygen is not needed for most of the above areas being investigated is that oxygen is transported on the hemoglobin molecule.
    Oxygen has a very strong affinity for hemoglobin.
    Even breathing room air with only a 20% oxygen content still results in a 99% oxygen saturation!
    And "too much" oxygen is harmful due to the excess oxygen free radicals that injure tissue.]

    Link to this
  3. 3. ChloePaltrow 1:42 am 01/10/2015

    Thanks for sharing some really good examples of sucessful treatment of various deseases with Hyperbaqric Chambers. I just want to add a few more.

    HBOT treatment is also very effective in treatment of Traumatic Brain Injury (TBI) and also for autism; though the later is not approved by FDA. With high quality chambers and proper guidance, patients with ASD, can recover a lot.

    I have gone through a recent article on Wall Street Journal which shows how the HBOT therapy from Oxyhealth helps to get some reliefs for autistic patients.

    Link to this
  4. 4. paulinawhite 7:23 am 01/12/2015

    Chloe,I have gone through the article in WSJ whre the writer Joseph Walker has clearly describes that how the pure oxygen in high atmosphiaric pressure in such chambers help the autistic patients to get some relief, though the fact is that, autism is not completely curable and the subject is under research as well, but the fact is that, HBOT therapy gives some sort of comfort to the patients with ASD.

    As mentioned in the article, I have gone through as well and keep a close view about their product line and objectives.

    I am quite impressed to find that, they took the security issues of their users as their prime level of consideration and does not compromise with the quality of the chambers and services.And yes, they are the leading HBOT chambers providers in USA till date.

    Link to this
  5. 5. ChloePaltrow 7:18 am 02/9/2015

    Thanks Paulina for visiting the WSJ post I have mentioned in my previous comment.

    Besides Oxyhealth, there are other health centers in California and Wisconsin, where the medical professionals help the patients in taking the hyperbaric treatment in their medical centers.

    Recently I have visited Wisconsin Integrative Hyperbaric Center ( Website : ) and meet the medical profesionals there. No doubt, they are highly expert and guide their patients well in their treatment.

    Link to this
  6. 6. docloveslife 11:42 am 02/13/2015

    Great article. Atlanta Hyperbaric Center in Atlanta is a awesome place.

    Link to this
  7. 7. dean12345 7:38 am 03/10/2015

    Excellent blog.
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