The Honest Answer

Is Hyperbaric Oxygen Therapy Safe?

For most people who are properly screened, HBOT is generally well tolerated. The published numbers support that: a StatPearls review of hyperbaric complications cites an overall adverse-effect incidence of around 0.4% in one monoplace series, and most of those effects were mild. Ear pain alone made up nearly half of the reported problems.

Well tolerated is not the same as harmless, though. HBOT changes the pressure around your body and raises the oxygen in your blood well above normal. That is the point of the therapy, and it is also why a small number of serious complications are possible. Safety depends on three things working together: a medical assessment before you start, a chamber built and run to recognized standards, and trained staff with you for every session.

At Generations Wellness, all three are in place. Care is directed by Dr. Rajwinder Singh Bahia, MD. You are treated in a hard-shell monoplace (single-person) chamber, breathing medical-grade oxygen at the pressure your physician prescribes. For background on the therapy itself, see how HBOT works.

What Can Happen

Side Effects of HBOT, and How Often They Happen

The figures below come from published medical reviews. They describe patients in general, not what will happen to you, and your physician will talk through your own risk at your assessment.

HBOT side effects with published frequency figures. Sources: StatPearls, Hyperbaric Complications; Heyboer et al., 2017.
Effect	How common	What it feels like	How it is handled
Middle-ear barotrauma	The most common complication; at least 2% in monoplace series. Ear pain made up nearly 50% of reported adverse events.	Fullness, then pain, in one or both ears as pressure rises	Clearing your ears early; pressurization slowed or paused; physician review if pain persists
Sinus barotrauma	Less common than ear problems	Pain and pressure over the cheeks or forehead	Screening for colds and congestion; a session may be postponed
Temporary nearsightedness	The most common effect on the eyes, building over many sessions	Distance vision becomes slightly blurry	Usually improves within about six weeks after the course; can take up to a year
Mild fatigue	Common	Feeling tired after a session	Rest; do not drive while drowsy
Confinement anxiety	About 25% of adverse-event reports; 8 per 10,000 treatments in one series	Feeling closed in or panicky	Preparation, communication, and the option to stop
Oxygen-toxicity seizure	Rare: about 1 per 5,000 to 10,000 treatments	A seizure while breathing oxygen under pressure	Oxygen is removed; the seizure typically stops once normal air is breathed
Cataract formation	Linked to very long courses, around 150 or more daily treatments in one study	Gradual clouding of vision	Your physician weighs this for unusually long courses
Pulmonary barotrauma	Rare, but the most serious type of barotrauma	Chest pain or sudden shortness of breath	Lung screening before treatment; emergency care if it occurs

For a deeper look at each effect, including how it is prevented, read our guide to HBOT side effects. If your main worry is your ears or feeling enclosed, see ear pressure and claustrophobia in HBOT.

Blurry vision after HBOT

Breathing oxygen under pressure day after day can temporarily change the shape and focusing power of the lens in your eye. The usual result is mild nearsightedness: things far away look a little soft. It develops gradually over a course, not after one session. According to StatPearls, it is considered fully temporary, with vision improving quickly within the first six weeks after treatment ends, although a complete return to your usual vision can take up to a year. Because your eyes are still changing, ask your physician before buying new glasses during a course.

Cataracts are a separate question. New cataract formation has been linked to very long exposures: one study suggests it starts after about 150 daily treatments, and another points to 300 to 850 hours of exposure. That is far longer than the typical 20 to 40 session course, but your physician will take it into account if a long course is ever being considered.

Oxygen toxicity: what it is and why it is rare

Oxygen is a drug, and like any drug, the dose matters. At high pressures, too much oxygen for too long can affect the brain and nervous system (central nervous system toxicity) or the lungs (pulmonary toxicity).

Seizures. The most serious form of central nervous system toxicity occurs about once every 5,000 to 10,000 treatments. StatPearls notes that these seizures typically stop once the patient breathes normal air, with no other intervention needed. A high fever or a seizure disorder can lower the seizure threshold, and so can the medication disulfiram, which is why all three are part of screening.
Lung irritation. Pulmonary oxygen toxicity shows up as irritation of the airways, ranging from a cough to a burning feeling behind the breastbone to shortness of breath. Treatment plans are designed to keep total oxygen exposure within safe limits.

Many hyperbaric protocols build in short periods of breathing air, often called air breaks, to lower the oxygen dose. Your physician sets the pressure and duration of every session with these limits in mind.

Eligibility

Who Should Not Use a Hyperbaric Chamber

The absolute contraindication: an untreated pneumothorax

An untreated pneumothorax, or collapsed lung, is the only condition that rules out HBOT entirely. The reason is Boyle's law: gas trapped in the chest compresses as pressure rises and expands again as pressure falls. When pressure is released at the end of a session, that trapped air can expand and turn into a tension pneumothorax, which can cause the heart and circulation to fail. This is why lung history is always reviewed first.

Relative contraindications: a physician must weigh them

A relative contraindication means HBOT is not automatically ruled out, but a physician must weigh your risks and benefits first. Sometimes the answer is yes with precautions, sometimes it is not yet, and sometimes it is no.

COPD or emphysema. Oxygen can reduce the drive to breathe in some people with COPD, and air trapped in damaged lung can raise the risk of a collapsed lung.
Asthma, blebs or bullae. Air trapping in the lungs can lead to a pneumothorax as pressure is released.
Seizure disorders and high fever. Both can lower the seizure threshold and raise the risk of oxygen toxicity.
Recent ear or chest surgery. Healing tissue may not tolerate pressure changes.
Colds, congestion and sinus infections. A blocked nose or sinuses makes it hard to equalize and raises the risk of ear and sinus barotrauma.
Trouble equalizing your ears. Eustachian tube problems may call for equalization training or, in some cases, small ear tubes placed by a specialist before a course.
Implanted devices. Most devices withstand chamber pressure, but confirmation from the manufacturer is recommended for pacemakers, defibrillators, pumps and similar devices.
Pregnancy. Traditionally treated as a relative contraindication. HBOT may still be considered in emergencies such as carbon monoxide poisoning, where the balance of risk is different.
Heart failure. HBOT can be given safely when heart failure is appropriately managed, which is why cardiac history is reviewed.
Claustrophobia. Depending on severity, it can be a barrier, though many anxious patients manage well with preparation.
Diabetes. Not a barrier on its own, but low blood sugar is a recognized consideration, and published guidance describes managing it with glucose monitoring.

Not sure where you stand? Call (369) 222-0979 and ask about a physician assessment. We will tell you honestly whether HBOT makes sense for you.

Medications that matter: bleomycin, doxorubicin, cisplatin, disulfiram and mafenide

A handful of medicines interact with high-pressure oxygen. Always bring a complete list, including anything you have taken in the past, especially chemotherapy.

Bleomycin (a chemotherapy drug) raises the risk of lung scarring. HBOT is generally considered acceptable once at least three to four months have passed since exposure and lung function is normal.
Doxorubicin (a chemotherapy drug) is usually held for at least 24 hours before HBOT.
Cisplatin (a chemotherapy drug) is associated with impaired wound healing, which the physician weighs.
Disulfiram (used for alcohol use disorder) blocks one of the body's defenses against oxygen damage, raising the risk of oxygen toxicity.
Mafenide acetate (a burn cream) can cause a build-up of carbon dioxide and acid in the blood.

Children, older adults and pregnancy

Many people who receive HBOT for wounds or radiation injury are older adults, and your physician looks at your overall health rather than your age alone. Children who may need HBOT should be assessed individually; if you are asking on behalf of a child, call us and we will tell you honestly whether our center is the right setting. Pregnancy, as noted above, requires physician evaluation, and elective treatment during pregnancy should only be considered after that conversation.

Equipment & Environment

Chamber Safety: Fire, Pressure Vessels and Standards

Why fire safety rules are strict

A monoplace chamber is filled with oxygen, and oxygen makes fire far more likely. Materials that barely burn in ordinary air can ignite easily, and a small spark matters. That is why the rules at our center are firm: 100% cotton clothing; no petroleum-based products, cosmetics, perfumes, hairspray, lotions or electronics inside the chamber; and jewelry, watches and electronics stay outside with our staff. These rules are not busywork. They are the main reason chamber fires are so uncommon.

The standards chambers are built and run to

NFPA 99, Chapter 14 is the fire-safety code for hyperbaric facilities. It classifies a single-occupant (monoplace) chamber as Class B and a chamber for two or more people, including an inside attendant, as Class A.
ASME PVHO-1 is the engineering standard for pressure vessels for human occupancy, the chamber itself.
The FDA regulates hyperbaric chambers as medical devices and has cleared them for a specific list of conditions.

Soft-sided "mild" chambers are a different category. They typically run at about 1.3 times normal pressure on air, below the level the Undersea and Hyperbaric Medical Society uses to define HBOT. See medical-grade vs. soft-shell chambers and our chamber, standards and staffing.

At Generations Wellness

How Screening Works at Our Center

A physician assessment before any course. Your history, condition and goals are reviewed, with no exceptions.
Ear, lung and medication checks. The contraindications above are reviewed one by one.
Device and records review. Bring device cards and records from your other doctors.
A check-in before every session. Tell us about any new cold, fever, congestion, ear pain or medication. A session may be postponed if it is not safe to go ahead that day.
Trained staff throughout. Staff are in communication with you for the entire session, and you can ask to stop at any point. Because pressure has to come down gradually, ending a session early takes a few minutes.

To see what a visit looks like from start to finish, read what happens at a first session, or browse short answers to common questions.

Regulation

Is HBOT FDA Approved?

The accurate wording is that the FDA has cleared hyperbaric chambers, which are medical devices, for a specific list of uses. That list includes air or gas embolism, carbon monoxide poisoning, decompression sickness, select non-healing diabetic wounds of the lower extremities, delayed radiation injury, compromised skin grafts and flaps, and several others. See the full list of FDA-cleared indications.

The FDA also states that HBOT has not been cleared for many conditions it is marketed for, including cancer, autism, Alzheimer's disease, stroke, brain injury, depression and COVID-19. It advises patients to be treated under a doctor's care at an accredited facility. When you see HBOT described as broadly "FDA approved," be cautious.

Important

A physician assessment is required before beginning HBOT at Generations Wellness. HBOT complements, and never replaces, the treatment prescribed by your doctors.

Questions

HBOT Safety: Frequently Asked Questions

Who should not use a hyperbaric chamber?

Anyone with an untreated collapsed lung must not. People with certain lung conditions, seizure disorders, active ear or sinus problems, some chemotherapy exposures, pregnancy or implanted devices need a physician's evaluation first.

What are the most common side effects of HBOT?

Ear or sinus pressure, mild fatigue, and temporary nearsightedness after many sessions. Serious effects such as oxygen-toxicity seizures are rare, at about 1 in 5,000 to 10,000 treatments.

Can I do HBOT with a pacemaker?

Possibly. Most implanted devices withstand chamber pressure, but confirmation from the manufacturer is recommended, so bring your device card to your assessment.

Can you do HBOT with COPD or asthma?

Sometimes, after evaluation. Air trapping raises the risk of a collapsed lung, and COPD can affect breathing on high oxygen, so your physician may want more information before deciding.

Is HBOT safe during pregnancy?

Pregnancy is a relative contraindication that requires physician evaluation. HBOT may be considered in emergencies such as carbon monoxide poisoning; elective treatment needs a careful conversation first.

Are hyperbaric chambers a fire risk?

Oxygen makes fire more likely, which is why medical chambers follow NFPA 99 rules. That means cotton clothing, no electronics, and no petroleum-based products inside the chamber.

Sources

StatPearls. Hyperbaric Complications. National Library of Medicine. ncbi.nlm.nih.gov
StatPearls. Hyperbaric Oxygen Therapy Contraindications. National Library of Medicine. ncbi.nlm.nih.gov
StatPearls. Hyperbaric Contraindicated Chemotherapeutic Agents. National Library of Medicine. ncbi.nlm.nih.gov
Heyboer M, et al. Hyperbaric Oxygen Therapy: Side Effects Defined and Quantified. Advances in Wound Care, 2017. pmc.ncbi.nlm.nih.gov
Undersea and Hyperbaric Medical Society. Standards and Codes (safety and technical FAQ). uhms.org
U.S. Food and Drug Administration. Hyperbaric Oxygen Therapy: Get the Facts. fda.gov
Undersea and Hyperbaric Medical Society. Position Statement on Low-Pressure Fabric Hyperbaric Chambers. uhms.org
University of Iowa Health Care. Hyperbaric Oxygen Therapy Resources for Providers. uihc.org

This page is educational and not medical advice. Frequency figures come from published studies and do not predict your individual risk. A physician assessment is required before HBOT. See our full medical disclaimer.

Keep Reading

Is Hyperbaric Oxygen Therapy Safe? Side Effects, Contraindications and Who Should Not Use a Chamber