Sinus squeeze is usually painful but not dangerous. Most episodes resolve on their own within a few days with basic care. However, in rare cases, sinus squeeze can lead to serious complications including nerve damage, infection spreading to the brain, or vision loss, particularly when divers continue pushing through symptoms or dive repeatedly with chronic sinus problems.
Nearly half of all divers experience sinus squeeze at some point. A large survey of 1,881 divers found that 48.9% had dealt with it, and among less experienced recreational divers, about one in four experienced an episode during training alone.
What Happens Inside Your Sinuses
Your sinuses are air-filled pockets in the bones of your face, connected to your nasal passages through small openings called ostia. When you descend underwater or an airplane drops altitude, the pressure around you increases. Normally, air flows through those openings to keep the pressure inside your sinuses balanced with the pressure outside.
If an opening is blocked, whether from a cold, allergies, swelling, or mucus, air can’t get in. The higher outside pressure creates a vacuum effect inside the sinus. That negative pressure pulls fluid from the tiny blood vessels in the sinus lining, causing the tissue to swell, fill with fluid, or bleed. This is the “squeeze.” You feel it as sharp pain in your forehead, cheeks, or around your eyes, and it sometimes produces a nosebleed.
The reverse can also happen. During ascent, trapped air inside a sinus expands as surrounding pressure drops. If that expanding air can’t escape, it compresses the sinus lining outward, causing pain and sometimes bleeding. This is called a “reverse squeeze.”
Mild vs. Severe Symptoms
A mild sinus squeeze feels like localized pressure or a sharp ache in the face, often above the eyes if the frontal sinus is involved, or in the cheeks for the maxillary sinuses. You might notice a small amount of blood in your mask or when you blow your nose afterward. This type of episode is common and typically clears up within a day or two.
More concerning signs include intense facial pain that doesn’t fade after surfacing, significant nosebleeds, numbness or tingling in the face (which can signal nerve involvement), swelling around the eyes, or visual changes. The fifth cranial nerve, which provides sensation to most of your face, runs near the sinuses and can be affected by severe barotrauma. If you notice any numbness, persistent swelling around your eye socket, or changes in vision after a dive or flight, you need medical evaluation promptly.
When Sinus Squeeze Becomes Dangerous
The rare but serious complications tend to happen in specific circumstances: diving with an active sinus infection, diving repeatedly despite ongoing sinus problems, or performing forceful equalization attempts against a blocked sinus. A forceful Valsalva maneuver can generate over 250 mm Hg of pressure, enough to force infected material through thin bony barriers separating the sinuses from the brain cavity, or to push air into the eye socket or middle ear.
Documented complications from severe or repeated sinus barotrauma include brain abscess from sinus infection spreading through bone defects, air trapped inside the skull (pneumocephalus), blindness from bleeding or pressure in the eye socket, and facial nerve palsy. In at least some published cases, permanent neurological damage occurred despite aggressive treatment. These outcomes are genuinely rare, but they underscore why pushing through sinus pain underwater is a bad idea.
Repeated diving with chronic sinusitis appears to cause cumulative damage. Researchers have speculated that ongoing exposure fosters permanent changes to the sinus lining and progressive narrowing of the sinus openings, making future episodes more likely and more severe over time.
Who Is Most at Risk
Certain physical traits and conditions make sinus squeeze more likely and potentially more severe. A deviated septum, nasal polyps, a history of a broken nose, chronic allergies, or an active upper respiratory infection can all narrow or block the sinus openings. If you regularly struggle to equalize or frequently get nosebleeds after diving or flying, these structural factors are worth investigating with an ear, nose, and throat specialist.
Less experienced divers face higher rates of sinus squeeze partly because equalization technique improves with practice, and partly because newer divers may not recognize early warning signs that signal it’s time to stop descending.
How Sinus Squeeze Is Treated
Most episodes need only basic management: over-the-counter pain relief, nasal decongestant sprays to reduce swelling and reopen the sinus passages, and saline nasal rinses. Steroid nasal sprays can help bring down mucosal swelling, and they’re particularly useful for people whose squeeze is related to nasal polyps. If there’s concern about a sinus infection contributing to the problem, antibiotics may be prescribed.
Recovery from a straightforward episode usually takes a few days to a week. There are no formal U.S. guidelines for recreational divers on exactly when to return to diving after sinus barotrauma, but the general principle is to wait until all pain and congestion have fully resolved and you can equalize easily on land before going back in the water. For comparison, lung barotrauma requires at least six months off diving, reflecting how much more serious that injury is. Sinus squeeze, while less severe in most cases, still warrants patience.
Preventing Sinus Squeeze
The single most important rule: don’t dive or fly with significant nasal congestion. If you can’t breathe clearly through both nostrils, your sinuses are unlikely to equalize properly. Using a topical decongestant spray or an oral antihistamine before a dive or flight can help keep passages open, though decongestant sprays shouldn’t be used for more than a few consecutive days.
For divers, equalization technique matters. The standard Valsalva maneuver, pinching your nose and blowing, is the most commonly taught method but has real drawbacks. It doesn’t actively open the tubes connecting your throat to your ears and sinuses; it just forces air against them. If there’s already a pressure difference building, blowing harder can lock those passages shut or even cause damage. Gentler alternatives include:
- Frenzel maneuver: Pinch your nose, close the back of your throat, and make a “K” sound. This uses your tongue to compress air upward rather than relying on brute force from your lungs.
- Toynbee maneuver: Pinch your nose and swallow. The swallowing motion actively pulls the tubes open.
- Lowry technique: A combination of pinching your nose, gently blowing, and swallowing simultaneously.
Whichever method you use, equalize early and often during descent, before you feel pressure building. Once a pressure differential locks the passages shut, no amount of blowing will fix it, and trying harder only increases your risk of injury. If you can’t equalize, stop descending and ascend slightly until the pressure releases. Pushing through pain is how mild squeeze turns into something more serious.