In hyperbaric oxygen therapy (HBOT), people are exposed to 100% oxygen at a higher-than-normal pressure.
Safety and precautions
Side effects or adverse events
Because oxygen is a radiosensitizer, HBOT can increase the risk of injury for people undergoing radiation therapy.1Bennett MH, Feldmeier J et al. Hyperbaric oxygenation for tumour sensitisation to radiotherapy. Cochrane Database of Systematic Reviews. 2018 Apr 11;4(4):CD005007. High levels of oxygen can also cause neurological problems (oxygen toxicity), including seizures.2Bennett MH, Feldmeier J et al. Hyperbaric oxygenation for tumour sensitisation to radiotherapy. Cochrane Database of Systematic Reviews. 2018 Apr 11;4(4):CD005007; Ward AJ, Stubbs B, Dixon B. Carcinoma of the cervix: establishment of a hyperbaric oxygen trial associated with the use of the cathetron. British Journal of Radiology. 1974 Jun;47(558):319-25.
HBOT can affect the ears (due both to pressure changes and oxygen toxicity to the nervous system) and the eyes; in one study, nearly half of all patients receiving HBOT had short-term vision or hearing loss.3Oscarsson N, Müller B et al. Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): a randomised, controlled, phase 2-3 trial. Lancet Oncology. 2019 Nov;20(11):1602-1614. In the long term, HBOT can also cause or worsen cataracts.4Bennett MH, Cooper JS. Hyperbaric Oxygen Therapy and Associated Cataracts. [Updated 2024 Jan 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-.
Finally, HBOT is dangerous for people with chest injuries or lung diseases such as COPD or emphysema, because if there is any air trapped in the chest, the pressure difference that HBOT creates can lead to a pneumothorax (lung collapse).5Gawdi R, Yrastorza J, Cooper JS. Hyperbaric Oxygen Therapy Contraindications. [Updated 2025 May 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-.
Interactions with other therapies
Some studies find that HBOT can increase the risk of radiation injury, though in some cases, it may also make radiation more effective.
Do not use (contraindications)
HBOT should not be used by people with chest injuries or illnesses that can trap air in the lungs, like COPD.
Keep reading about hyperbaric oxygen therapy
Learn more
References