Claustrophobia in a Hyperbaric Chamber: What to Expect and How to Cope

Studies estimate about 25% of patients experience some confinement anxiety during HBOT. That’s not a small number. And it doesn’t mean most of those people quit treatment.

With the right preparation and support, the majority of anxious patients complete their full protocol. The key is telling your care team before you start — not after your first panic response inside the chamber.

What the Chamber Actually Looks Like

There are two main types of hyperbaric chambers, and they feel very different.

A monoplace chamber holds one patient. It’s an acrylic tube, roughly the size of a large MRI machine. You lie inside while it pressurizes with 100% oxygen. Staff stay outside but can see you clearly through the acrylic and can communicate with you throughout the session. You can stop the session at any time by signaling the technician.

A multiplace chamber holds multiple patients — sometimes up to 12. It’s pressurized with air. You breathe 100% oxygen through a mask or hood. Medical staff can be inside the chamber with you. It feels much more like a room than a tube.

For anxious patients, multiplace chambers are generally more comfortable. Not all facilities have them. It’s worth asking before you book.

What Clinics Do to Help

Good hyperbaric programs prepare anxious patients before the first full session.

Most offer an acclimation session — a shortened, sometimes unpressurized or lightly pressurized introduction to the chamber. You get inside, get comfortable with how it feels and sounds, and staff walk you through what to expect. Many patients who felt anxious beforehand found the acclimation session reduced their fear significantly before real treatment began.

Music and TV are standard in modern monoplace chambers. Most facilities let you watch a show or listen to music for the entire 90-minute session. That helps a lot. A session goes faster with something to watch.

Communication stays open throughout. If you need to stop, you tell the technician and the session ends. You’re not locked in.

For patients with significant pre-existing anxiety, a short-acting benzodiazepine before sessions is a reasonable option. This requires a physician’s prescription. Talk to your hyperbaric physician and your regular prescriber together — medication timing and interactions need to be reviewed.

When Claustrophobia Is a Contraindication

Severe, untreated claustrophobia can make HBOT impractical or unsafe. If a patient is in acute distress, unpressurizing takes time, and the physiological stress response during a panic episode inside a pressurized chamber creates risks.

This doesn’t mean everyone with claustrophobia is excluded from treatment. It means severe claustrophobia that can’t be managed with preparation and medication may prevent safe participation. Your hyperbaric physician will assess this.

Be honest with your care team. Tell them about your anxiety before the first session. They can’t help you manage something they don’t know about.

Practical Tips Before Your First Session

Ask the facility which type of chamber they use. If they have multiplace capability and you’re anxious, request it.

Take a virtual tour or look up photos of the specific chamber model before your appointment. Knowing what it looks like removes some of the unknown.

Ask whether an acclimation session is available. Not every facility offers this automatically — you may need to request it.

If your anxiety is significant, discuss pre-medication with your care team before your first session. Don’t try to get through the first full session on willpower alone if you have serious concerns.

Bring headphones if you’re in a monoplace chamber. Ask whether the facility has built-in TV or whether you can use a personal device inside the chamber (not all facilities allow external electronics due to fire safety protocols — ask first).

FAQ

Can I stop the session if I panic? Yes. Signal the technician and they’ll begin the controlled depressurization process. You won’t be stuck. Depressurization takes a few minutes — it can’t be instantaneous because of decompression safety — but you can communicate with staff throughout.

Will claustrophobia get better or worse over multiple sessions? For most patients who push through early anxiety, it improves with familiarity. Subsequent sessions are typically less stressful than the first once patients know what to expect and how it feels.

Can I bring someone into the chamber with me? In monoplace chambers, no — they hold one person. In multiplace chambers, a family member can sometimes accompany a patient if the facility allows it and if they’ve been medically cleared. This is particularly relevant for pediatric patients. Ask your facility directly.

Medical Disclaimer: This page provides general information about managing anxiety during HBOT. It’s not medical advice. If you have severe anxiety or panic disorder, discuss treatment options with your physician before starting HBOT. Medication decisions require a physician’s evaluation.

Related guides: What to Expect at Your First HBOT Session | Monoplace vs. Multiplace Chamber