by Scholten A
(Hyperbaric Oxygenation; Hyperbarics; Hyperbaric Medicine; HBOT; HBO2)


Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen in a sealed chamber. In the chamber, oxygen levels and pressure are higher than normal. This can help improve the flow of blood and oxygen to the body's tissues.

Reasons for Procedure

This procedure has been used to treat many health problems, such as:

Carbon Monoxide Poisoning
Carbon monoxide poisoning
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Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Mild discomfort
  • Nearsightedness (for weeks or months)
  • Damage to structures and organs
  • Oxygen toxicity, which can cause seizures and lung problems

What to Expect

Prior to Procedure

The care team may advise:

  • Comfortable clothes
  • A book or activity to do in the chamber

Description of the Procedure

You will lie down on a padded table, which slides into a tube. This is called a single-person chamber. In some cases, the chamber may be large, holding more than a dozen people.

A technician will slowly pressurize the chamber with 100% oxygen. You will be able to talk to this person. While in the chamber, you will be instructed to:

  • Relax and breathe normally.
  • Tell the technician if your ears pop or you have discomfort. The pressure may be lowered.
  • Swallow or blow with your nose pinched—to ease discomfort.
  • Place a clear plastic hood or mask over your head—when the pressure is right. This will deliver oxygen to you.

Some are at high risk for oxygen toxicity. If so, they may be able to breathe normal air for brief periods.

How Long Will It Take?

½ hour to 2 hours

Will It Hurt?

There should not be any pain. Some have fullness in the ears.

Average Hospital Stay

Most can go home the same day. Those with other conditions may need to stay longer.

Post-procedure Care

For most, there is no special care after treatment.

Call Your Doctor

Call your doctor if you are not feeling well or have:

  • Discomfort or pain in your sinuses or ears
  • Onset of seizures
  • Vision problems
  • Problems breathing or chest pain

If you think you have an emergency, call for medical help right away.


Divers Alert Network 

Undersea and Hyperbaric Medical Society 


Alberta Health 

Health Canada 


Hyperbaric oxygen therapy: A guide for patients and providers. University of Iowa Health Care website. Available at: Accessed September 30, 2021.

Hyperbaric oxygen therapy for critical care in adults - acute indications. EBSCO DynaMed website. Available at: Accessed September 30, 2021.

Hyperbaric oxygen therapy for wound healing. Johns Hopkins Medicine website. Available at: Accessed September 30, 2021.

Kirby JP, Snyder J, et al. Essentials of hyperbaric oxygen therapy: 2019 review. Mo Med. 2019;116(3):176-179.

Recompression therapy. Merck Manual Professional Version website. Available at: Accessed September 30, 2021.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 07/2021
  • Update Date: 09/30/2021