Top 6 Side Effects of Hyperbaric Oxygen Therapy

//Top 6 Side Effects of Hyperbaric Oxygen Therapy
  • HBOT Side Effects

When you’re in a pressurized capsule…how does your body react?

When many people learn about HBOT, they have immediate concerns. Do therapy sessions in a pressurized chamber do anything bad to your body?

It’s a good question.

Hyperbaric oxygen therapy (HBOT) has minimal side effects when performed at a professional facility.

In one year-long study, side effect rates were only 0.4%. In that same study, half of all adverse side effects were ear pain. A quarter of the side effects were claustrophobia.1

So what side effects can you get from hyperbaric therapy?

1. Eye issues (hyperbaric oxygen therapy vision changes)

It’s not well understood why the hyperbaric environment. We do know that vision changes are a common side effect. Many resolve on their own once you’re done with hyperbaric therapy.

Some eye-related side effects include:

  • Myopia (trouble seeing objects far away)
  • Eyelid twitching
  • Blurry vision
  • Faster-developing cataracts

Your HBO therapists will regularly assess your vision to see if you’re having any changes. Your HBOT physician will also help you develop a plan if you’re especially at risk for vision changes.

 2. Sinus squeeze (HBOT sinus barotrauma)

Any air-filled cavity in your body can feel the effects of a pressure change. This can include but isn’t limited to your nasal sinuses, bowels, bladder, lungs, and teeth.

Normally, your body adjusts to pressure changes very effectively. People comfortably travel in airplanes, in submarines, and down mountains all the time.

The issues come up if the pressure change is too fast, or something in your body is blocking your pressure-equalizing systems.

A sinus infection, congestion, and a deviated septum make you more at risk of sinus squeeze during hyperbaric therapy. If the squeeze is particularly intense, it can cause pain in your cheeks, eyes, and/or forehead and a nosebleed.3

This is easily prevented by reviewing your risks with your doctor before your session. Let them know if you have congestion or infection. The squeeze can also show up in your teeth, so let them know if you’ve had recent dental work.

If you’ve been cleared to go forward with your therapy session, use ear clearing techniques to comfortably adjust to the pressure.

3. Claustrophobia

This is one of the most common side effects1—but it’s usually predictable.

If you don’t generally feel claustrophobia, likely, you won’t feel claustrophobic in a hyperbaric chamber. If you struggle with claustrophobia, then the hyperbaric chamber may be a challenge.

Thankfully, HBO therapy is not like getting an MRI. You don’t have to deal with the stress of staying still in a chamber you can’t see through. You’ll be able to see all around you. And have more space than you would than sitting in the passenger seat of your car.

Since claustrophobia is such a common concern, your HBOT physician will thoroughly assess whether the therapy is compatible with your tolerance. You may be able to tour the chamber before choosing to begin HBOT.

If you’re already in the chamber and you can’t stand it, your HBO therapist will be ready to take you out. Depressurizing will take about 10 minutes for your safety, but you always have the right to promptly end a session. 

4. Hypoglycemia

It’s not well understood, but blood sugar levels tend to go down when you’re in a hyperbaric oxygen chamber.4

This is a common side effect partially because there’s a strong overlap between diabetics and individuals needing HBOT. Thankfully, the hypoglycemia trends are fairly predictable. Your HBOT therapist may recommend that you have a higher-than-normal blood sugar just before your sessions.

If you’re diabetic, your HBOT therapist will ask you what your blood sugar was before your therapies. If it’s too low, your session may need to be rescheduled. Appropriate assessment and care could get delayed if your blood sugar were to dip too low while you were sealed in the hyperbaric chamber.

5. Ear pain (middle ear barotrauma from hyperbaric oxygen therapy)

During normal hyperbaric therapy, you’ll feel pressure in your ears. However, it’s not normal to have pain. You should be able to comfortably clear your ears by swallowing, drinking water, gently pinching your nose, and blowing.

For some people, the pressure shift may be painful, even with ear-clearing exercises. If your ear pressure isn’t relieved, it can advance to more pain, and possibly a ruptured eardrum.

That’s why it’s crucial to tell your HBO therapist if:

  • You have or just recovered from a cold or flu.
  • You have an ear infection.
  • You’ve got water trapped in your ear.
  • You have lots of wax in your ear.
  • Your ears regularly hurt when you travel in an airplane or down a mountain.

Typically, ear pain is easy to avoid. Avoid ear-pressure risks and do ear-clearing techniques during your session. Your HBO therapist will also help by slowly bringing you up and down from the pressure. They’ll also check your ears for waxy blockages before your therapy.

Don’t hesitate to immediately tell your HBOT therapist if you’re having ear discomfort. They can slow or halt the pressure change and guide you with ear-clearing.

6. Fatigue

We’ll frequently hear patients ask “Why am I tired after my hyperbaric treatment?” 

HBOT has a strange effect on people’s energy. Some people feel rejuvenated and full of energy after their therapy. But many people feel exhausted, even if they took a nap during their session.

An HBOT session works your mitochondria extra hard5, which may be why you become so fatigued. It’s similar to when you take an exam and feel tired afterward, even though you weren’t physically active.

How to avoid hyperbaric oxygen therapy side effects

Always tell your doctor about your surgeries, sicknesses, and medications, and about how you’re currently feeling. Tell them about past and recent procedures. Talk about whatever is making you feel nervous or concerned about your therapy options.

Interested in hyperbaric oxygen therapy in Georgia?

If you or your doctor has been looking for an accredited hyperbaric oxygen medicine facility, then look no further. Set up an appointment or get your questions answered at (770) 422-0517.

[We can’t guarantee outcomes or side effects you might experience or avoid from HBOT. This article was written to inform, not replace medical advice or provide a diagnosis. We strongly recommend talking to a doctor about your medical needs.]


By | 2021-05-07T12:32:37-04:00 April 27th, 2021|Hyperbaric Oxygen Therapy|0 Comments


During this pandemic, we will try and minimize risks to patients and staff. Guidance changes frequently, so we may need to change our recommendations over time.

We ask that all patients come into the office wearing a mask. Masks may be removed at the instruction of the staff for hyperbaric oxygen therapy.

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