Red blood cells travel throughout your body, carrying necessary nutrients and gases to all of your tissues and organs. One of the gases they carry is oxygen, which your body uses to maintain healthy tissues and repair damaged ones.

Your doctor may recommend hyperbaric oxygen (HBO) therapy for many different medical conditions. They may recommend HBO therapy if you have a wound that isn’t healing at a normal rate. For example, diabetes and radiation injuries can cause wounds to heal too slowly. HBO therapy helps deliver high levels of oxygen to your tissues, which promotes healing.

When you enter an HBO chamber, your body is exposed to 100 percent oxygen and a higher level of air pressure than normal, explains John Hopkins Medicine. This stimulates healing at a much faster rate as it delivers a much higher concentration of oxygen to the tissue that’s not possible under the normal conditions in your body.

Your doctor may prescribe HBO to encourage wound healing. They may prescribe it to help your body fight infection. They may also use it to provide oxygen to tissues that have been damaged due to exposure to carbon monoxide.

For example, your doctor may recommend HBO therapy several times per week for a few weeks if you have burns, gangrenous wounds, or a radiation injury.

Your doctor may also recommend HBO therapy for decompression sickness, which is usually caused by one of the following:

  • diving
  • carbon monoxide inhalation
  • a stroke
  • a traumatic brain injury

HBO therapy can be delivered in a one-person chamber, where you lie down on a table or bench, which slides into a clear plastic tube. Multi-person chambers, where several people can sit or lie down inside, are also available at certain medical facilities.

Inside the chamber, you receive 100 percent oxygen. The air pressure in the chamber is also higher than usual. All you need to do is lie or sit in the chamber while breathing in the oxygen. Your treatment session may last anywhere from one to two hours. You may need multiple sessions depending on your condition.

The risks of HBO therapy are low. However, it does carry some risks and potential side effects.

For example, serious fires and explosions are more likely to happen in environments filled with 100 percent oxygen. You’ll be instructed to not bring anything into the HBO chamber that could easily start or catch fire. Examples include:

  • lighters
  • matches
  • battery-powered devices
  • hair care products
  • petroleum based products

If you have a question about whether or not you can bring something into the chamber, ask your doctor or HBO chamber specialist.

During HBO therapy, you may feel pressure build up in your ears. In rare cases, you may experience more severe side effects, such a seizure caused by excess oxygen in your central nervous system.

Other potential side effects include temporary nearsightedness, ear injuries such as eardrum rupture, and injuries to your lung, such as a pneumothorax, which is a collapsed lung.

Let your doctor know if you start to feel discomfort or pain during HBO therapy as this may be a sign of a side effect of the treatment.

You may need multiple sessions of HBO therapy for it to be effective. It’s often used along with other treatments. Your treatment plan and results will vary, depending on your specific condition. For example, if you have a wound that hasn’t been healing as fast as it should, your doctor may recommend HBO therapy along with other treatments, such as wound care, bandaging, and antibiotics. Your wound may require 25 to 30 sessions of HBO therapy before it fully heals.

Inhalation injuries often require fewer HBO therapy sessions than slow-healing wounds. For example, a single, significant exposure to carbon monoxide will require only one session of HBO therapy. Additionally, people who experience decompression sickness, or the bends, usually will only require one session to improve their symptoms significantly. In general, the more chronic the medical condition, the more sessions of HBO are required to achieve effect.

Talk to your doctor to learn more about your specific treatment plan and outlook. They can help you learn how many sessions of HBO therapy you may need. They can also prescribe other treatments if you need them.