How To Prevent Sinus Squeeze When Diving? Key Facts

Sinuses are air-filled spaces inside the bones of your face, and they must stay equalized with the surrounding water pressure for a dive to be comfortable. The way to prevent sinus squeeze is simple in principle: keep the small openings that drain your sinuses clear, and stop your descent the moment you feel pressure or pain you cannot relieve. Diving while congested is the most common cause of the problem, and it is entirely avoidable.

What Is Sinus Squeeze and Why Does It Happen?

Sinus squeeze is a form of barotrauma. It happens when pressure outside your body does not match pressure inside the air-filled sinus cavities.

As you descend, water pressure rises. The air in your sinuses compresses. To keep things balanced, air from your nose and throat must flow through narrow drainage channels called sinus ostia into those cavities. If those channels are blocked or narrowed, the pressure inside the sinus cannot match the pressure outside it. The result is a suction-like effect on the sinus lining, which is packed with blood vessels and nerve endings. That is what produces the pain.

Four pairs of sinuses sit around your nose and eyes: the frontal sinuses above the eyebrows, the maxillary sinuses in the cheeks, the ethmoid sinuses between the eyes, and the sphenoid sinuses deeper behind the nose. Any of them can be affected, but divers most often feel squeeze in the frontal and maxillary areas. That is partly anatomy — those ostia are small and take a winding path, which makes them easier to block.

Descent is when squeeze usually strikes. Rising pressure needs air to move inward. But squeeze can also happen on ascent, when expanding air needs to escape and cannot. Some divers describe this as reverse squeeze. The mechanism is the same blocked channel — the direction of the pressure difference is just flipped.

What Causes Sinus Squeeze in Divers?

A blocked sinus ostium is the root cause, and the blockage almost always comes from swelling or mucus in the nasal lining. Anything that inflames that lining raises your risk.

• An active cold, flu, or sinus infection
• Allergic rhinitis, whether seasonal or year-round
• Nasal polyps or a deviated septum that narrows drainage
• Recent nasal surgery, before healing is complete
• Certain medications, including some that dry or swell the nasal lining
• Smoking, which irritates and inflames nasal tissue

One point that surprises many divers: the problem is not always obvious on land. You can feel perfectly clear sitting on the boat and still have swollen sinus tissue that closes off under pressure. Mild congestion that you barely notice at the surface can be enough to block an ostium once you descend.

There is a related condition worth knowing about. If a blocked sinus does not equalize and you keep descending, the lining can bleed into the sinus cavity. Divers sometimes notice blood in their mask or when they clear their nose after a dive. That is a sign the squeeze was significant, and it means you should not push through it again on the same day.

What Does Sinus Squeeze Feel Like?

The hallmark is pain in the forehead, cheek, or behind the eyes that starts during descent and gets worse the deeper you go.

Other common signs include:

• A feeling of pressure or fullness in the face
• Pain that eases when you stop descending or ascend slightly
• Bloody mucus after the dive
• Numbness or a dull ache over the cheek or brow that lingers

Pain that keeps getting worse as you go down is the key signal. It is different from the pressure you feel in your ears, which usually clears with a gentle equalizing technique. Sinus squeeze does not respond to ear-clearing maneuvers, because the problem is in different air spaces.

If the pain is severe, or if you have numbness, vision changes, or symptoms that do not improve after the dive, that warrants medical evaluation. In rare cases, significant sinus barotrauma can cause complications that need a clinician’s attention.

How To Prevent Sinus Squeeze When Diving

Prevention starts before you get in the water. The single most effective step is to not dive when your nose is congested.

That sounds obvious, but it is the advice divers most often ignore. A stuffy nose from a cold, allergies, or a sinus infection means the ostia are already narrowed. Pressure will make it worse. Sitting out a dive is far better than risking injury to your sinuses.

Beyond that, these steps reduce your risk:

• Manage allergies ahead of a dive trip, working with your doctor on a plan that keeps nasal swelling down.
• Avoid smoking and secondhand smoke, which inflame the nasal lining.
• Descend slowly and stop at the first sign of pressure you cannot relieve.
• Ascend a little if you feel pressure building, give your sinuses a moment, and try again gently.
• Stay hydrated, since dry airways can thicken mucus and make drainage harder.

Some divers use nasal saline rinses or sprays to keep passages moist and clear. Saline is generally considered low risk. Decongestant sprays and pills are a different matter and deserve their own discussion below.

Should You Use Decongestants Before a Dive?

This is where divers most often get into trouble, and the standard advice is to be cautious.

Decongestant medications shrink swollen nasal tissue, which can open the ostia and let you equalize. The problem is what happens when the medication wears off. As the drug’s effect fades, the nasal lining can swell back — sometimes more than before. This is called rebound congestion. If that happens while you are underwater, a sinus that was open on descent can suddenly close on ascent, trapping expanding air. That is a recipe for a squeeze or a reverse squeeze.

Because of this, many diving medicine sources advise against relying on decongestants to dive through an active cold or infection. The medication can mask a problem that is still there. If you are considering any medication before a dive, that is a conversation to have with a doctor familiar with diving medicine, not a decision to make on the boat.

This is a good place to draw a clear line. There is a difference between managing a chronic condition like allergies under medical guidance and using a pill to force your way into the water while sick. The first is reasonable. The second is how people get hurt.

What If You Feel Sinus Pressure During a Dive?

Stop descending. That is the whole answer, and it is not negotiable.

Continuing to go down against pain forces the pressure difference to grow and increases the chance of injury to the sinus lining. Ascend slightly, give it a moment, and see if the pressure eases. If it does not, end the dive. No dive is worth a sinus injury.

If you surface with pain that does not settle, blood in your mucus, or facial numbness, get medical attention. Most mild cases improve on their own over hours to a few days as the swelling goes down, but a clinician can assess whether something more is going on. Do not dive again until you are fully clear and symptom-free.

When Should You See a Doctor About Sinus Problems and Diving?

If sinus squeeze keeps happening even when you feel well, the underlying issue may need a closer look.

Recurrent squeeze can point to a structural problem — nasal polyps, a deviated septum, or chronically narrow ostia — that a doctor can evaluate. An ear, nose, and throat specialist can examine your nasal passages and, in some cases, order imaging. Some of these issues can be treated, which may make diving more comfortable.

You should also see a doctor if you have ongoing sinus infections, chronic congestion, or facial pain that does not go away. These are worth addressing for your daily health, not just for diving.

It helps to be honest with yourself about your body’s signals. Divers who repeatedly get squeeze often have a treatable cause. Finding it is better than working around it dive after dive.