Ear discomfort is common when scuba diving, but pain is not an unavoidable part of the activity. Pain or pressure during descent signals improper pressure management. Understanding the cause of this pressure change is the first step toward prevention. By learning and practicing the correct techniques, divers can safely and comfortably explore the underwater world without ear trouble.
The Physics of Pressure and Your Ears
Ear discomfort during a dive results from the rapid increase in surrounding water pressure affecting the body’s air spaces. Boyle’s Law explains this phenomenon: the volume of a gas decreases as pressure increases. Since water is much denser than air, the ambient pressure increases quickly, with every 33 feet (10 meters) of descent in saltwater adding another atmosphere of pressure.
The middle ear is an air-filled cavity separated from the external ear canal by the eardrum, or tympanic membrane. As a diver descends, the increasing external water pressure pushes against the eardrum, causing it to bow inward. This creates a pressure differential because the air pressure in the middle ear remains at the lower surface level.
The Eustachian tube connects the middle ear to the back of the throat and is the body’s natural mechanism for regulating this pressure. This tube, which is normally closed, must be actively opened to allow higher-pressure air from the throat to enter the middle ear space. If the pressure is not equalized, the eardrum continues to stretch inward, leading to discomfort that quickly progresses to intense pain, a condition known as middle-ear squeeze or barotrauma.
Mastering Equalization Techniques
Equalization is the deliberate act of opening the Eustachian tubes, allowing air to flow into the middle ear and balance the pressure. The most widely taught method is the Valsalva maneuver, where the diver pinches the nostrils closed and gently attempts to blow air through the nose. This forces air into the nasopharynx and up the Eustachian tubes, creating a distinct “pop” sensation.
A more controlled and often gentler technique is the Frenzel maneuver, which involves pinching the nose and using the muscles at the back of the tongue and throat to push air into the tubes. This technique is preferred by some experienced divers because it does not require a forceful exhalation from the lungs. Another option is the Toynbee maneuver, where the diver pinches the nose and swallows, which helps to pull the Eustachian tubes open.
Equalization must be performed proactively, beginning immediately upon descent and continuing frequently—ideally every few feet—before any discomfort is felt. Waiting until pain starts means the pressure differential has already built up, making the tube more difficult to open. Divers should descend slowly and in a head-up position, which facilitates easier equalization. If an attempt fails, ascend slightly until the pressure eases before trying again gently.
Signs of Ear Trouble and When to Stop
Failing to equalize the middle ear can lead to ear barotrauma, an injury that ranges from mild discomfort to severe damage. The first signs are a feeling of fullness or “clogged” ears, which quickly escalates to sharp, throbbing pain with continued descent. If the pressure imbalance is not corrected, it can cause fluid and blood to leak into the middle ear space.
A more serious indication of ear trouble is a sudden onset of dizziness or vertigo, a disorienting spinning sensation often accompanied by nausea. This symptom suggests potential damage to the inner ear, which regulates balance, and requires immediate attention. In severe cases, the eardrum may rupture, which can cause hearing loss and expose the sterile middle ear to water and potential infection.
If a diver experiences pain or finds they cannot equalize after ascending a few feet and trying again, they must immediately stop the descent and abort the dive. Forcing the equalization maneuver when the ear is already under stress can worsen the injury and potentially cause trauma to the inner ear. Furthermore, divers should avoid entering the water if they have a cold, allergies, or any form of congestion, as swollen nasal passages can block the Eustachian tubes and make equalization impossible.