What is a Hyperbaric Chamber and What Does it Do?

What is a hyperbaric chamber

Hyperbaric chambers have long been associated with the treatment of decompression sickness, also known as "the bends." If you’ve ever gone scuba diving, you were probably warned about the risks of decompression illness, a condition that strikes divers who surface too quickly.

Related: Rehabmart's Ultimate Guide to Hyperbaric Oxygen Therapy (HBOT)

But recent (and not so recent) developments in hyperbaric technology has led to the expansion of their use beyond treating decompression sickness, into FDA-approved territory and, yes, even the homes of some celebrities and sports figures.

Michael Jackson bought one in 1984 after being burned while filming a Pepsi commercial and he allegedly slept in it every night. But, Michael Jackson was an odd, unpredictable pop star. He did a lot of crazy things, right?

Sure, he lived a life that perplexed many people. But did you know that even professional athletes have spoken publicly about using hyperbaric chambers? Lance Armstrong, for instance, claims that he uses one to recover from cycling races.

Health doesn’t always come in the form of a pill, even though pharmaceutical companies might want you to believe something entirely different. Now more than ever, patients across the globe are seeing past drug company marketing hype and evaluating alternative options.

All hype aside, for many people, hyperbaric chambers have made the difference between living a normal life and being disabled for the rest of their days.

Not only can hyperbaric chambers speed up the body’s healing process, they can also improve circulation, help fight infection and treat various neurological disorders.

What Exactly Is a Hyperbaric Chamber?

Hyperbaric chambers are vessels in which patients breathe oxygen at pressures up to three times greater than normal atmospheric pressure. They are used to treat divers suffering from decompression illness or to administer hyperbaric oxygen therapy, also known as HBOT.

The vessels are about 3 feet in diameter and 8 feet long, so they are big enough for people to enter and exit easily. Patients can watch TV or listen to ambient music to keep themselves entertained during the treatment, which can last up to two hours.

Although oxygen therapy might be a novelty for most of us, the concept is certainly not new. Documentation shows that breathing hyperbaric oxygen as therapy has been around for nearly 350 years.

The first hyperbaric chamber was created in 1662, by British physician Hank Henshaw. He named it "Domicilium." Henshaw discovered quickly that the reduced pressure of "Domicilium" benefited chronic illnesses while acute disorders responded better to increased pressure.

It wasn’t until the mid-1800s that clinical use of hyperbaric oxygen therapy started. Decades later, the military developed and tested hyperbaric chambers for purposes related to deep sea diving and aeronautics.

During the 1960s, studies took a more general approach, highlighting the broad application of hyperbaric chambers. Nowadays, medical research and clinical studies continue to find more uses of this remarkable and versatile therapy.

The Food and Drug Administration recommends hyperbaric oxygen therapy for a handful of medical conditions, including:

Carbon monoxide poisoning
Gas embolism
Brain injuries
Crush injuries
Skin grafts
Radiation damage

Related: What the FDA Says about Hyperbaric Oxygen Therapy (HBOT)

Although hyperbaric chambers have been widely used for more than 100 years in countries across the globe, they have been restricted in the United States. These days, however, more than 30,000 HBOT treatments are done each day, across the country.

What Is the Principle of Hyperbaric Oxygen Therapy?

Hyperbaric oxygen therapy is a medical treatment that entails the use of oxygen at increased pressures for therapeutic purposes. The treatment is administered in hyperbaric chambers where pure oxygen is (sometimes) circulated.

The air we breathe at sea level contains only 21% oxygen. The oxygen we breathe in is temporarily incorporated in the red blood cells and transported to tissues and cells.

However, injury or disease may disturb this process, depriving tissues and cells of some or all of their required oxygen. When this happens, normal atmospheric pressure is not strong enough to force the necessary amount of oxygen deep into the body’s tissues.

Hyperbaric oxygen therapy enables the body to absorb much more oxygen by saturating the blood plasma. As a result, oxygen is pushed beyond the red blood cells, directly into all the damaged tissues, jump starting the healing process.

In addition to saturating the blood plasma, breathing oxygen under elevated pressures has proven to be beneficial for multiple medical conditions. HBOT enhances the body’s white cells’ capacity to kill bacteria and fight infection. It also speeds wound repairing and recovery by promoting the growth of new blood vessels.

Increased oxygen supply can also help individuals suffering from air embolism, decompression sickness, burns, cerebral edema, diabetic wounds, gas gangrene, stroke, and many others. More than that, it’s a great way to keep your skin looking young and vibrant.

However, you need to be prudent. Although HBOT can help heal several conditions, it’s no magic bullet. To learn if you are suited for this therapy you need to talk with your doctor. Also, always make sure the treatment is administered in a clinical setting.

Types of Hyperbaric Chambers

In the early days of HBOT, doctors and researchers used a ready-made pressure vessel similar to a boiler. They were built from steel and manufactured to endure high levels of internal pressures.

Some years later, the American Society of Mechanical Engineers (ASME) came up with new standards for the design and construction of pressure vessels, making them more safe and better suited for human use.

Modern hyperbaric chambers generally fit into two main categories: monoplace and multiplace. A few manufacturers also build portable hyperbaric chambers for emergency treatments in remote areas.

Monoplace Hyperbaric Chambers

Monoplace hyperbaric chambers were first introduced in the 1960s. Made of clear acrylic material and shaped like a cylinder, they were designed to accommodate only one patient.

During the treatment, the monoplace chamber is filled with 100% pure oxygen and the atmospheric pressure is increased to up to three times higher than normal. Transparent walls allow the clinical staff to monitor the patient closely and minimize discomfort for those with claustrophobia.

Because the time and access in a monoplace chamber is limited, they are used for less severe cases of injuries or decompression illness.

One of the primary disadvantages of monoplace chambers is that the patient is isolated and confined in a relatively small place. It might be a bit difficult to endure a two-hour session, especially if you are claustrophobic.

Multiplace Hyperbaric Chambers

Though more expensive than monoplace chambers, and with more hands required to operate, multiplace chambers are a popular option in hospitals and medical centers. With enough room for up to 18 patients and the ability to treat various conditions, patients can relax in a chair or recline comfortably while breathing oxygen through a face mask, hood or endotracheal tube. The pressurized atmosphere is normal air in a multiplace chamber.

Technicians attend to patients during treatment to monitor their signs and symptoms and administer drugs and fluids as needed. Staff can enter or exit the chamber during a session through doorways that can be independently pressurized.
One of the main advantages of multiplace chambers is that they allow for extended treatment times. As a result, they are suited for patients who are in convalescence and need time to heal.

Portable Chambers

People who suffer from decompression sickness caused in scuba diving accidents need to be treated in a hyperbaric chamber, but often the closest treatment facilities are hundreds of miles from remote diving destinations.

Portable hyperbaric chambers are designed for emergency treatments and patient transportation. They’re lightweight, inflatable and can be used with an air compressor. A major disadvantage of portable hyperbaric chambers, however, is that they can only be pressurized to 3 ATA, limiting their use.

With this in mind, manufacturers have developed large transport hyperbaric chambers. Their steel construction increases their weight and sturdiness and allows them to be pressurized up to 6 ATA, expanding their treatment potential to more injury types and medical conditions.

What’s it Like to be Treated in a Hyperbaric Chamber?

Every patient’s experience is different. For some, climbing into a monoplace chamber feels like climbing into a coffin, while others find the entire experience pleasant and comfortable.

Before your session, you’ll be asked to change into scrubs. If the medical center doesn’t offer you scrubs, be sure to wear cotton clothing.

Don’t bring the following items into the chamber:

Lighters or matches
Hairspray or hair oil
Contact lenses
Hearing aids

Enter the chamber when you’re ready. In a monoplace chamber, you’ll lie down as your technician rolls your bed into the vessel. In a multiplace chamber, you can either sit in a chair or lie on a bed.

As the treatment begins, you’ll feel air slowly being pushed into the chamber. You’ll probably feel a fullness in your ears, which is normal and similar to the feeling you get in an airplane. Have your technician walk you through some techniques for relieving ear pressure.

As the pressure inside the chamber increases and you begin to inhale pure oxygen, you’ll start to feel a sense of euphoria. All you have to do is sit back and let the oxygen do its work. You can listen to music, watch TV, take a nap, read a book or meditate.

As your session ends, the air inside the chamber will be slowly released. You’ll feel your ears pop again as the pressure returns to normal levels. Overall, hyperbaric treatments are not painful, but some patients may feel claustrophobic. In extreme cases, your medical technician may administer a mild sedative to help you relax.


Co-Founder of Rehabmart and an Occupational Therapist since 1993. Mike has spent his professional career working in multiple areas of Occupational Therapy, including pediatrics, geriatrics, hand therapy, ergonomics and inpatient / outpatient rehabilitation. Mike enjoys writing articles that help people solve complex therapeutic problems and make better product choices.

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