The chamber does the work. The one thing it asks of you is to keep your ears even as the pressure changes — the same trick you already use on a plane. Here’s how, and what to do on the rare day your ears or sinuses complain afterward.
Your ears and sinuses are small pockets of air. As pressure rises, that air wants to shrink; as pressure falls, it wants to grow. Keeping them comfortable just means letting the air move freely in and out — and the move is opposite on the way down versus the way up. At 1.5 ATA the total swing is gentle (about 7 psi, like diving to eleven feet), so this is easy — but the biggest volume change per unit of pressure happens nearest the surface, which is exactly the start of the descent and the end of the ascent. Those are the moments to pay attention. It’s gentle pressure here, so it’s easy — just know that the two directions need two different moves, and most people only ever learned the first one.
Pressure-related irritation of the middle ear or sinuses is called barotrauma — literally “pressure injury.” In mild hyperbaric it’s the most common side effect and almost always minor: a blocked passage couldn’t equalize, so the lining got stretched. Expect fullness, a dull ache over the cheek or brow, or a sense of congestion. It usually settles over hours to a few days. Pressure can leave an ear or sinus feeling sore, full, or congested — like a head cold that won’t quite clear. It’s the most common minor side effect, and it usually eases on its own over hours to a few days. Here’s how to be kind to it.
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Don’t
Most of the time, rest is all it needs. But please get checked — and tell us — if any of these show up. The last row is the one that matters most: it gets seen the same day.
| What you notice | What to do |
|---|---|
| Pain that isn’t improving after a day or two, or getting worse | Have a clinician take a look — an ear/nose/throat (ENT) doctor is ideal. |
| A little blood from the nose or ear | Common with sinus barotrauma but confirms mucosal injury — see an ENT, and no pressure exposure until cleared. Worth an ENT visit, and no flying/diving/sessions until you’re cleared. |
| Fever, thick or colored discharge, spreading facial pain | Could be a sinus infection — see a clinician. |
| Any change in hearing, ringing in the ear, or dizziness / spinning — especially together or sudden | Possible inner-ear barotrauma (round- or oval-window injury / perilymph fistula) — a true emergency and time-critical for hearing. Stop all straining: no Valsalva, no nose-blowing. Urgent same-day ENT. Don’t wait. Stop any nose-blowing or ear-popping and get same-day medical care. This one is rare but time-sensitive for your hearing. |
Now and then someone notices an old spot speak up — a long-ago dental filling, a sinus that was operated on years back. There are two different reasons, and both are usually harmless.
Trapped air. A tiny gas pocket under an old filling or behind worn dental work obeys the same physics as your ears — it changes volume with pressure and can give a brief twinge. That one has a name: barodontalgia (older texts call it aerodontalgia). Air-containing spaces left or altered by past surgery can register a pressure change the same way. There’s no special term for “feeling an old scar” — it’s just trapped gas doing what trapped gas does. A small bubble of air under an old filling follows the same rules as your ears — it shifts a little with pressure and can give a brief twinge. (Dentists actually have a word for it: barodontalgia.) Old surgical spots that still hold a pocket of air can do the same. Nothing’s wrong — it’s just air being air.
Returning circulation. Separately — and this one is more story than science — some people describe an old injury or scar briefly tingling as oxygen-rich blood reaches tissue that had gone quiet. A plain scar holds no trapped air, so this isn’t a pressure effect; if it’s anything, it’s the ordinary healing response, and the evidence for it is anecdotal rather than proven. We mention it only so a faint, passing hello from an old seam doesn’t alarm you. Anything sharp, persistent, or worrying — tell us.
Pairs with what to expect & the full safety page.