Is hyperbaric oxygen therapy safe?

When administered by trained operators following established protocols, HBOT has a strong overall safety record across millions of treatments. The most common side effect is ear pressure discomfort (barotrauma), similar to what you experience during airplane descent, which affects roughly 2-5% of patients. This is managed by teaching equalization techniques and controlling the rate of pressurization. Temporary myopia (near-sightedness) can occur during extended treatment courses but typically resolves within weeks of completing therapy. Other uncommon side effects include sinus pressure, temporary changes in vision, and fatigue after sessions. Oxygen toxicity — the most serious potential risk — is extremely rare at standard treatment pressures and durations, occurring in less than 0.01% of treatments. Seizures related to oxygen toxicity are exceedingly rare and typically resolve without lasting effects. Contraindications include untreated pneumothorax, certain chemotherapy drugs (bleomycin, cisplatin, doxorubicin), and some ear conditions. Patients with claustrophobia may find monoplace chambers challenging, though facilities often accommodate this with transparent chambers, communication systems, and pre-treatment familiarization. Always use facilities with proper chamber maintenance records, trained operators, and emergency protocols. Look for accreditation from organizations like the Undersea and Hyperbaric Medical Society (UHMS).

Reviewed by Chad Waldman, Analytical Chemist · Last updated May 2026

About Hyperbaric Oxygen Therapy

HBOT delivers 100% oxygen at 1.