How to Equalise Your Ears Scuba Diving: Techniques, Problems and Fixes

This article is general information, not medical advice. For ear pain, hearing changes or dizziness that do not clear, see a doctor, ideally one with diving-medicine experience.

Ear trouble is the most common reason a new diver's first descent goes wrong, and one of the most common reasons experienced divers miss a dive. The good news is that equalising is a skill, not a gift. Almost everyone who can clear their ears on an aeroplane can learn to do it underwater, and most "problem ears" turn out to be a timing problem: the diver waited too long, went down too fast or went down head-first. This guide explains what is happening inside the ear, how to perform each of the main equalising techniques, a descent routine that prevents most problems, what to do when one ear refuses to clear, and how to tell a harmless sensation from a warning sign.

Why your ears hurt underwater

The middle ear is a small, rigid, air-filled space behind the eardrum. Its only connection to the outside world is the Eustachian tube, a narrow passage that runs from the middle ear to the back of the nose. For most of the day that tube stays closed; it opens briefly when a person swallows or yawns.

At the surface, air pressure on both sides of the eardrum is the same. As a diver descends, the water pressure rises by about one atmosphere for every 10 metres of seawater. Boyle's law says that a gas squeezed by higher pressure takes up less space, so the air trapped in the middle ear shrinks. Because the bony walls cannot move, the eardrum is pulled inward. That stretching is the pressure and then the pain divers feel. The fix is to open the Eustachian tube and let air from the throat flow into the middle ear until the pressure on both sides matches again. That is equalisation.

The crucial detail is where the change happens. The pressure doubles from 1 bar at the surface to 2 bar at 10 metres, halving the volume of the trapped air. Going from 20 to 30 metres changes pressure from 3 to 4 bar, a much smaller relative step. In other words, the shallow part of the descent is where the ears need the most attention, and where most problems begin. According to DAN, a pressure difference of about 0.35 bar can be enough to rupture the eardrum in some divers, and that difference builds up in just the first few metres if nothing is done.

There is a second reason timing matters. When the pressure difference grows, the soft tissue around the throat end of the Eustachian tube is pressed shut. Past a certain point the tube is effectively locked, and blowing harder does not open it. Divers who "can't equalise" have very often simply waited too long.

Six equalising techniques, step by step

All the techniques do the same job: open the lower end of the Eustachian tubes so air can get in. They differ in how. Divers Alert Network (DAN) describes six main methods. Most divers learn one at their first course, but it pays to learn two or three, because the one that works on a fresh morning may not work on day five of a dive trip.

1. Valsalva

The classic method taught on most courses. Pinch the nostrils (or press the nose pocket of the mask) and blow gently through the nose with the mouth closed, as if blowing the nose into the closed nostrils. A soft pop or click in the ears means air has entered. It works for many divers, but it has drawbacks: it relies on lung pressure rather than the muscles that open the tubes, it is easy to blow too hard, and blowing hard against a blocked tube can stress the inner ear. DAN advises against holding a Valsalva for more than about five seconds.

2. Toynbee

Pinch the nostrils and swallow. Swallowing pulls the tubes open while the tongue compresses the air in the throat. The Toynbee manoeuvre is also useful on the way up, because it can help air escape from the middle ear during ascent. Many divers find it easier with a small sip of water or by swallowing on the regulator.

3. Frenzel

Pinch the nostrils and close the back of the throat, as if straining to lift something heavy, then make the sound of the letter "k" or push the back of the tongue upward. The tongue acts like a piston and pushes air into the Eustachian tubes without using the lungs. Freedivers rely on it because it works at any depth, and many scuba instructors regard it as gentler and more efficient than the Valsalva once learned.

4. Lowry

A combination of Valsalva and Toynbee: pinch the nose, then blow gently and swallow at the same time. It takes some coordination but can work when either method alone does not.

5. Edmonds

Push the jaw forward and down, which tenses the throat muscles and helps open the tubes, then perform a Valsalva or Frenzel at the same time. Small head movements, tilting one ear toward the surface, can also help the higher ear clear.

6. Voluntary tubal opening (BTV)

The hands-free method, sometimes called by its French name béance tubaire volontaire. The diver tenses the muscles of the soft palate and throat, as at the start of a yawn, while pushing the jaw slightly forward, which pulls the tubes open without any pinching or blowing. According to DAN, up to about 30 percent of divers can master it, but it takes a lot of practice.

A useful test of whether a technique is working: on land, a successful equalisation usually produces a slight pop, a click, or a feeling of fullness in both ears at once. If only one ear responds, try tilting the head so the stubborn ear is uppermost.

A descent routine that prevents most problems

Most ear injuries in divers are avoidable with a calm, deliberate descent. The routine below combines the advice of DAN and standard dive training.

• Start before the dive. Gently equalise a few times while gearing up and again at the surface just before going down. This "pre-pressurises" the middle ear and confirms that both tubes are open.
• Go down feet first. DAN advises descending feet first where possible. With the head up, air rises naturally toward the Eustachian tubes; head-first descents make equalising noticeably harder for many divers.
• Equalise early and often. DAN suggests equalising gently every few feet through the first 10 to 15 feet (roughly 3 to 5 metres). In practice many divers equalise about every half metre to metre, or with each breath, through the first 10 metres, and then whenever any fullness returns.
• Equalise before it hurts. Discomfort means the pressure difference is already building. Pain is a signal to stop, not to push on.
• Control the speed. A descent line, a mooring rope or a reef slope gives something to hold on to and a visual depth reference. A slow, controlled sink is far easier on the ears than a fast drop into the blue.
• Do not bounce. Repeated ups and downs in shallow water mean repeated pressure swings. Once down, stay at a steady depth.
• Watch the hood and the mask. A tight hood can seal over the ear canal and trap air outside the eardrum; lift the edge to let water in. A mask pulled too tight can make it hard to pinch the nose.

Buoyancy matters too. A diver who is overweighted tends to sink faster than their ears can follow, while good neutral buoyancy makes it easy to pause at any depth and equalise. A dive computer showing the depth in real time also helps divers notice how fast they are descending.

When one ear won't clear

Almost every diver meets a stubborn ear sooner or later. The response is the same every time:

1. Stop descending and signal the buddy or guide (pointing at the ear is the usual signal).
2. Ascend a metre or two until the pressure or discomfort eases. Less pressure outside means the tube is easier to open.
3. Try again gently, ideally with a different technique: switch from Valsalva to Frenzel, swallow, push the jaw forward, or tilt the blocked ear toward the surface.
4. Descend again slowly once both ears have cleared, equalising more often than before.
5. If it still will not clear, end the dive. DAN's guidance is simple: if a diver cannot equalise, the dive should be aborted. There will be other dives; a damaged eardrum can mean weeks out of the water.

What must never be done is forcing it: blowing hard against a blocked tube, or continuing down while the ear hurts. Forceful equalising is a recognised cause of inner ear injury, which is far more serious than a sore eardrum. A guide or instructor will always prefer a diver who turns back early to one who pushes through.

If one particular ear causes trouble on every dive, or equalising is difficult even on land, it is worth having the nose and ears checked by a doctor. Issues such as a deviated septum, nasal polyps or chronic allergies can narrow the passages and are often treatable.

Colds, allergies and decongestants

A cold, sinus infection, hay fever or allergy swells the lining of the nose and the Eustachian tubes. DAN lists upper respiratory infections, allergies, smoking and a deviated septum among the conditions that can compromise equalisation. A tube that opens easily on a healthy day may stay shut when it is inflamed, which raises the risk of ear and sinus barotrauma on the way down and of a trapped-air reverse block on the way up.

The safe choice is not to dive until the symptoms have cleared. It is a frustrating rule on a holiday, but a single forced dive with a cold can cost the rest of the trip.

Decongestants are a common temptation. DAN's position is cautious: medication can wear off during a dive, which can lead to a reverse block on ascent, and divers should not use decongestants before diving unless they have used them before and know how they react. Repeated use of over-the-counter nasal sprays can also cause a "rebound" effect, with congestion returning worse than before. Some medications also cause drowsiness, which has no place underwater. Anyone considering medication for diving should discuss it with a doctor first.

For a wider look at which health conditions affect diving, including previous ear surgery and perforated eardrums, see the Can I dive? health and fitness self-check.

Ascending: the reverse block

On the way up the process runs in reverse. The air in the middle ear expands and normally escapes on its own through the Eustachian tube, which is why divers rarely need to do anything to equalise during ascent. Occasionally, though, the tube will not let the expanding air out. This is a reverse block: the diver feels pressure, fullness or pain in the ear, and sometimes dizziness, as one ear vents and the other does not. It is most often linked to congestion or a decongestant wearing off during the dive.

The response is the opposite of panic:

• Stop the ascent and, if needed, descend slightly to ease the pressure.
• Try the Toynbee manoeuvre (pinch and swallow), jaw wiggling or tilting the affected ear down. Do not blow against the pinched nose, which adds air rather than letting it out.
• Ascend very slowly, a little at a time, letting the ear vent.
• Keep breathing normally throughout and watch the air supply and dive computer. Holding the breath or rushing to the surface creates far greater dangers than an uncomfortable ear.

Sudden dizziness when one ear vents before the other is called alternobaric vertigo. It usually passes within seconds or minutes, but it is disorientating; holding on to a line or reef and staying close to the buddy helps until it settles. Dizziness that does not pass is a reason to end diving and seek medical advice.

Outer, middle and inner ear problems

"My ear hurts after diving" can mean three very different things. Knowing which part of the ear is involved helps decide whether it can wait or needs a doctor today.

Outer ear: swimmer's ear (otitis externa)

An infection of the ear canal, the passage outside the eardrum. Repeated immersion over several days softens the skin lining the canal, letting bacteria that normally live there invade. It typically builds up over a day or two of diving, with itching, then pain that gets worse when the outer ear is pulled or pressed, and sometimes discharge or muffled hearing. It is not a pressure injury. Rinsing the ears with fresh water and drying them gently after diving helps; some divers use drying drops recommended by a doctor. Aggressive cleaning with cotton buds can scratch the canal and make infection more likely. Once an infection has set in, it usually needs treatment from a doctor and a break from diving.

Middle ear barotrauma ("ear squeeze")

The classic diving ear injury, and widely described as the most common injury among divers. It happens when the pressure behind the eardrum is not balanced, usually on descent. Symptoms start during the dive: pain, a sense of fullness or water in the ear, muffled hearing, and sometimes a little blood from the nose or ear. In more severe cases the eardrum ruptures; cold water entering the middle ear can then cause sudden dizziness. Mild squeezes often settle within days, but any ear that still hurts, sounds muffled or shows blood should be checked by a doctor before diving again.

Inner ear barotrauma: the warning signs

The inner ear contains the delicate organs of hearing and balance. Large pressure differences, often from forceful equalising or a fast descent, can damage it. DAN lists the signs as vertigo (often severe, sometimes with nausea and vomiting), hearing loss and tinnitus (ringing or roaring in the ear). These symptoms can be similar to inner ear decompression sickness, and only a doctor can tell them apart. Any of them after a dive means:

• stop diving immediately;
• do not try to equalise or blow the nose forcefully;
• seek medical attention promptly, ideally from a diving doctor or an ear, nose and throat specialist, and mention the dive profile.

Inner ear injuries can cause lasting hearing loss, so they are never something to sleep off.

Practising on land and the mask squeeze

Equalising can be practised anywhere. Pinching the nose and gently trying each technique in front of a mirror, a few times a day in the week before a trip, builds the muscle control that makes it automatic underwater. The simple test of success is a soft pop or click in both ears. Yawning, chewing and swallowing exercises help with the Frenzel and the hands-free method. On dive days, starting to equalise gently on the boat, before the gear goes on, gives sluggish tubes a head start.

Practice should always be gentle. Blowing hard repeatedly on land can irritate the ears just as it can underwater.

A related sensation is the mask squeeze. The air inside the mask also shrinks on descent, pulling the mask against the face. The fix is simple: breathe out a little through the nose into the mask from time to time on the way down. Divers who forget can end up with red marks around the eyes or small burst blood vessels in the whites of the eyes, which look alarming but usually fade on their own. Learning to breathe gently into the mask goes hand in hand with mask clearing, and a mask that fits well makes both easier; the guide to choosing a dive mask covers fit in detail.

For new divers, equalising is one of the first skills practised in confined water on a Discover Scuba Diving experience or the PADI Open Water course. The account of what learning to dive really feels like describes those first descents from a beginner's point of view, and the complete guide to scuba diving the Red Sea covers where to put the skill to use.

Related: Read what learning to dive really feels like, the diving health and fitness self-check and the guide to choosing a dive mask.

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