HBOT risks and side effects: what to ask before treatment

Medical assessment before treatment

Ear and sinus discomfort, temporary vision changes, and anxiety in an enclosed chamber are among the concerns to discuss before HBOT. Serious complications can occur. Your clinician should review your health, medicines, and the proposed treatment, then explain how the expected benefit compares with your risks.

Ask who completes your assessment and who is responsible for prescribing and supervising care. Request a plain-language explanation of what the team needs to review before proceeding. Bring your current health information rather than relying on an intake form completed months earlier. A new illness, operation, or medication may be worth discussing even if it appears unrelated to the condition being treated.

This guide helps prepare questions. Your treating team must provide the chamber-specific screening, preparation, and follow-up instructions. Do not use a general article to decide whether you can safely enter a chamber or to make independent changes to prescribed care.

Possible effects of pressure and oxygen

Mayo Clinic describes most complications as mild and temporary, while serious complications are uncommon. Its patient guidance lists ear pain and middle-ear injury, sinus symptoms, temporary changes in sight, cataracts with long treatment courses, a short-term decline in lung function, and low blood sugar in people using insulin for diabetes. It also identifies lung collapse and oxygen-related seizures as more serious complications.

Being inside an enclosed chamber can cause anxiety or claustrophobia. Tell the team about that concern before the session so you can discuss communication and support. Ask how you will alert staff to discomfort and what happens if you need the treatment interrupted. You should understand the response process before it becomes necessary.

Ask the clinician which effects are most relevant to your health and which symptoms should be reported immediately. Request instructions that distinguish concerns during a session from concerns after leaving the facility. A general risk list cannot tell you what caused a particular symptom or whether it can wait until the next appointment.

Conditions that require screening

Untreated pneumothorax, a collapsed lung that has not been treated, is an absolute contraindication described in the contemporary clinical reference cited here. Other histories may require additional assessment rather than permanent exclusion. Tell the clinician about lung disease, previous lung collapse or chest surgery, ear or sinus problems, recent ear surgery, infection or fever, and difficulty tolerating enclosed spaces.

Provide a complete medication and device list, including prescriptions, over-the-counter products, implanted devices, and equipment worn on the body. Also disclose pregnancy, diabetes management, seizure history, and heart disease. These are topics for clinical screening; their inclusion in a checklist does not mean each automatically makes HBOT unsuitable.

This list helps you prepare for screening; it cannot clear you for treatment. Ask the treating clinician to apply current evidence and the specific chamber’s instructions to your circumstances.

FDA’s August 2025 fire safety letter

On August 25, 2025, FDA issued a letter about safe use of HBOT devices after reports of fires causing serious injuries and deaths. The letter said the causes were unknown at publication and that serious adverse events were believed to be rare. The practical message is that high-concentration oxygen requires careful fire prevention and device operation.

FDA recommends following the manufacturer’s instructions, using proper grounding, maintaining staff training, monitoring and supervising patients throughout treatment, and completing recommended cleaning, maintenance, and safety checks. It also addresses prohibited electrical or static-producing items and clothing compatible with the manufacturer’s instructions. Ask how those safeguards are applied at the location you are considering.

Before entering, ask the team to screen what you are wearing or carrying. Obtain its instructions for hair and skin products, electronics, batteries, dressings, and medical equipment. Follow the facility’s approved clothing process and ask staff whenever you are uncertain about an item. A familiar item should still go through the team’s screening.

Monitoring, communication, and follow-up

Ask who observes you throughout the exposure and how you can speak with that person. Clarify who can assess a clinical problem, what emergency equipment and procedures the facility has, and how a transfer would happen if care is needed elsewhere. These questions are useful whether the chamber holds one person or several.

Before agreeing to a course, ask how changes in your condition will be reviewed between visits. Know whom to contact about symptoms, what information to report, and where to seek urgent care according to the team’s instructions. Request a written contact plan that works outside regular office hours.

A good consent discussion leaves room for questions and for another opinion. Record the expected benefit, your personal risks, the alternatives, and the reason for any proposed follow-up assessment. If an answer remains unclear, ask for clarification before committing. You do not need to select chamber settings or oxygen dosing yourself to take an active role in the decision.

Questions to ask

• What in my history or medication list needs further assessment?
• How will I communicate discomfort during treatment?
• What items and products require screening before chamber entry?
• What is the emergency plan and whom do I contact after leaving?

Sources