How Long Is an HBOT Session?

A common practical question before starting hyperbaric oxygen therapy is simply how long you will be in the chamber. The answer matters for planning your day, especially since a course of treatment usually involves many sessions. This guide explains the typical length of an HBOT session and what fills the time. It is general educational information, not medical advice, and your own facility will give you the exact schedule for your treatment.

The Typical Session Length

A standard hyperbaric oxygen therapy session commonly lasts around two hours, though the exact time varies by the facility, the condition being treated, and the specific protocol. The treatment protocol sets the pressure and the time at that pressure, and those are chosen based on established medical guidelines for the condition, not picked arbitrarily.

It helps to think of the session in parts. There is the time spent pressurizing the chamber to the treatment pressure, the time held at that treatment pressure breathing oxygen, which is the main part of the therapy, and the time spent gradually returning to normal pressure at the end. The bulk of the session is the time at treatment pressure, with the pressurization and depressurization adding time at each end. Add it together and a typical session occupies a couple of hours of your day, which is why our guides on how many sessions and the overall treatment course emphasize planning for the time commitment.

What Happens During the Session

For much of the session, you are resting in the chamber breathing oxygen according to the protocol. People often pass the time resting, relaxing, or in some monoplace chambers watching a screen, and many find they can rest or even doze, as our guide on sleeping during HBOT discusses. The experience is generally calm once you are settled at pressure.

Some protocols include scheduled air breaks, short periods of breathing regular air rather than the treatment oxygen, which are built into the session for safety reasons related to oxygen exposure, as our guide on oxygen toxicity explains. The pressurization at the start is when you equalize your ears to the changing pressure, the part our first session guide prepares you for. The depressurization at the end brings you gently back to normal pressure. None of this is rushed, which is part of why the full time at pressure plus the pressure changes adds up to the typical session length.

The Appointment Is Longer Than the Session

One thing worth planning for is that your total time at the facility is longer than the time in the chamber. Beyond the session itself, there is checking in, any pre-session screening, changing into appropriate garments, getting settled in the chamber, and the wrap-up afterward. So while the session might be around two hours, the full appointment can take longer when you account for the surrounding steps.

This matters for scheduling, especially for a treatment course involving daily or near-daily sessions over weeks. Planning your day around the full appointment rather than just the chamber time keeps the schedule realistic, and for people who must travel for treatment, as our guide on traveling for HBOT discusses, the total time commitment is a real factor. Knowing the appointment is longer than the session helps you arrange work, transportation, and the rest of your day.

Ask Your Facility for the Specifics

Because session length and protocol vary, your treating facility is the place to get the exact numbers for your situation. They can tell you how long your sessions will run, how many sessions your treatment course involves, and how often, based on the protocol for your condition. Knowing these specifics up front lets you plan the practical side of treatment with confidence.

The short answer to how long an HBOT session lasts is generally around a couple of hours at the facility, with the bulk of it spent resting at treatment pressure, plus the pressurization and depressurization at each end and the check-in and wrap-up around it. It is a meaningful but manageable commitment, and planning your days around the full appointment makes a course of treatment far easier to fit into your life. Your facility will give you the precise schedule, and this page offers general information rather than medical advice.

Medical Disclaimer: This page provides general educational information about hyperbaric oxygen therapy session length. It is not medical advice. Your treatment facility will provide the specific schedule and protocol for your care.

Sources: FDA, Hyperbaric Oxygen Therapy: Get the Facts | Undersea and Hyperbaric Medical Society