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People who undergo hyperbaric oxygen therapy (HBOT) report mild to no side effects from the treatment, according to a University of Maryland Medical Center article. Still, all medical procedures carry the risk of side effects.

Some people describe a feeling of lightheadedness immediately following their session. This feeling generally lasts a few minutes, so most were able to return to their daily activities with no additional issues.

In rare cases, vision changes can occur due to pressure changes in the delicate tissue of the eye. Side effects reportedly subside within 6 to 8 weeks after treatment.

Most side effects of HBOT are mild and subside soon after treatment is complete.

Claustrophobia is an intense emotional reaction triggered by the phobia of small or crowded spaces. The enclosed space of a pressurized chamber can trigger anxiety and feelings of claustrophobia.

Newer versions of the hyperbaric chambers are made from clear acrylic, which allows visibility throughout the room. The clear shell of the chamber gives you a full view of your surroundings at all times.

If small spaces give you the ick, let your clinician know ahead of your appointment. They can prescribe medication to help you relax during your treatment.

The average session lasts about 2 hours, and a trained healthcare professional is in the room the entire time. If you need assistance, they can be reached by intercom almost instantly. Many people sleep, watch a movie, or listen to music during treatment.

A monoplace chamber is designed for one person. If you’re uncomfortable with small spaces, some treatment centers have a multiplace chamber to treat more than one person at a time. Check with your individual treatment center to explore your options.

You might feel weakness and fatigue following hyperbaric treatment. This is expected and should dissipate after a short rest.

Talk with a doctor or other healthcare professional if these side effects persist or are affecting your quality of life. Your treatment plan may need to be revisited.

People with diabetes might experience a drop in blood sugar during treatment. In this case, glucose levels are monitored during the session to ensure safety.

Eating before the appointment can help maintain blood sugar levels and curb post-treatment symptoms.

The change in air pressure could temporarily change the shape of the lens of the eye. The change usually makes nearsightedness worse, but can improve age-related changes that affect the ability to focus your eyes.

These changes are temporary, and the eye will usually revert back to its pre-treatment shape within 6 to 8 weeks.

There are rare cases of the eyesight never reverting back to its pre-treatment stage.

The pressure inside of a hyperbaric chamber can feel like the changes in pressure felt during an airplane descent. The atmosphere may cause the ears to become pressurized and feel like they need to “pop.”

Middle ear trauma is one of the most common side effects of HBOT.

The Eustachian tube, which connects the middle ear to the sinuses, must be manually opened to release this pressure. Swallowing or chewing forces the valve open and releases the air inside, stabilizing the pressure.

If too much pressure builds up in the middle ear, the eardrum will start to warp and bow inward. In rare cases, this could lead to a perforated eardrum or hearing loss.

Sinus pain is the second most commonly reported side effect of HBOT.

The sinuses contain air-filled chambers, much like the ear. When pressure changes on one side of that chamber, it can cause a sinus squeeze.

This change in pressure causes the sinus to become inflamed. The swollen sinuses can block the nasal passageways leading to congestion, facial pain, and edema.

If the pressure in the sinus cavity cannot be equalized, it can lead to extreme pain in the face and bleeding into the sinuses. These symptoms are rare and can be managed with a decongestant nasal spray, antihistamines, or a steroid nasal spray.

If you have an air pocket in the tooth, the pressure changes during treatment can cause tooth pain near the root.

This change, known as “tooth squeeze,” can happen during compression or decompression. Too much pressure can build up inside the tooth causing a dental fracture.

Other possible causes of tooth squeeze include sinusitis, dental infections, and recent dental work.

Research on tooth squeeze has mostly studied aircraft personnel, air passengers, and divers outside of hyperbaric therapy.

A dental evaluation before your appointment can help prevent the symptoms of tooth squeeze before they start. A hyperbaric medical physician can perform a dental examination to ensure you’re a good candidate for treatment.

You may be more likely to experience pulmonary symptoms if you have:

Lung overinflation could cause air to leak into the chest cavity, leading the lung to collapse. The excess air in the chest cavity may lead to difficulty breathing and decreased blood pressure.

The lungs could also leak air into the blood vessels, causing an embolism. Gas bubbles in the blood could travel to the heart and other organs blocking fresh blood flow. An embolism can be fatal if untreated.

The high concentration of oxygen in a hyperbaric chamber may be too much for the lungs to handle. The lungs are breathing in 100% oxygen.

Prolonged exposure to increased levels of oxygen could lead to difficulty breathing, chest pain, and even respiratory failure.

Pulmonary oxygen toxicity shouldn’t be expected during routine daily HBOT, but the possibility of development does exist with prolonged exposure

The levels of oxygen supplied inside the chamber could overload the central nervous system. This could trigger a seizure. This is a rare occurrence, and the seizure usually subsides when the supply of supplemental oxygen stops.

All medical procedures carry some risk of side effects. Most side effects of HBOT are mild and subside not long after treatment is complete.

Some illnesses may increase the chance of experiencing more severe side effects. People who have recently undergone any type of dental or ear surgery (or injury), have certain types of lung disease, or have a history of a collapsed lung may experience more severe side effects from HBOT.

All HBOT facilities must be certified by the Undersea and Hyperbaric Medicine Society. Ask your treatment center about the appropriate certifications to ensure they’re following federal guidelines.

Pressurized oxygen is highly flammable and can result in an explosion if handled incorrectly.


Catasha Gordon is a sexuality educator from Spencer, Oklahoma. She’s the owner and founder of Expression Over Repression, a company built around sexual expression and knowledge. You can typically find her creating sex education materials or building some kinky hardware in a fresh set of coffin nails. She enjoys catfish (tail on), gardening, eating off her husband’s plate, and Beyoncé. Follow her everywhere.