Experiencing pain or discomfort during a dive descent signals that the pressure in your air-filled spaces is not equalizing with the surrounding water pressure. This phenomenon, known as barotrauma, occurs due to the relationship between pressure and gas volume described by Boyle’s Law. As a diver descends, ambient pressure increases, causing the volume of air inside the body’s non-rigid cavities to decrease. If air cannot enter these spaces to compensate for the reduction in volume, the resulting pressure difference pulls on the surrounding tissue, causing discomfort or injury. Responding immediately is crucial, as forcing a descent while experiencing pain can lead to serious physical damage.
Immediate Action Protocol
The instant a diver feels any sensation of pressure, fullness, or pain during descent, they must stop the downward movement immediately. Continuing to descend risks intensifying the pressure differential. After stopping, signal the discomfort to your buddy or dive team, then ascend a short distance, typically just a few feet, until the pain completely resolves.
Once the pain has dissipated, attempt gentle equalization again, using whichever technique is most effective. If successful, resume the descent, but at a significantly slower rate. If the pain returns, or if the initial gentle equalization attempt is unsuccessful, ascend again until the discomfort disappears and end the dive safely.
Pinpointing the Location of Pain
The most frequent site of barotrauma is the middle ear, often called middle ear squeeze or aural barotrauma. This air space is connected to the back of the throat by the Eustachian tube, which must open to allow air to enter and equalize the pressure. Symptoms begin as a feeling of fullness or “clogged” ears, which rapidly progresses to a sharp, intense pain if the descent continues. Severe cases can result in the eardrum bulging inward or bleeding into the middle ear. A rupture of the tympanic membrane may cause temporary relief of pain but also lead to vertigo and hearing loss.
The second most common issue is sinus squeeze, or barosinusitis, affecting the air-filled cavities within the face and skull. Pain from a sinus squeeze is felt as a localized headache or a distinct pressure sensation in the forehead, cheeks, or above the upper teeth. This occurs when the small openings, or ostia, that connect the sinuses to the nasal passages become blocked, often by inflammation or mucus. The resulting pressure difference can cause the lining of the sinus cavity to swell and bleed, which a diver might notice as bloody discharge in their mask upon ascent.
A third type of pressure-related discomfort is mask squeeze, or facial barotrauma, caused by the failure to add air into the mask’s air space. As a diver goes deeper, water pressure pushes the mask tightly onto the face, creating a relative vacuum inside the mask. This suction effect can cause the blood vessels in the soft tissues around the eyes to become engorged and burst. Symptoms include noticeable pressure on the face, red or bloodshot eyes, and bruising around the orbital area.
Addressing Underlying Causes and Future Prevention
The primary cause of descent barotrauma is the inability of the body’s air spaces to equalize pressure, which is most often linked to pre-existing congestion. Diving with a cold, allergies, or an upper respiratory infection significantly increases the risk, as the inflamed, mucus-filled tissues can block the narrow Eustachian tubes and sinus ostia. Even mild congestion that is barely noticeable on land can act like a plug, preventing the necessary air exchange underwater.
Improper or delayed equalization technique also contributes significantly to a squeeze injury. Many divers wait too long to begin the equalization process, only attempting it once they already feel pain or pressure. This delay is problematic because a pressure differential of just two pounds per square inch is enough to cause substantial discomfort and make successful equalization more difficult.
Future prevention focuses on meticulous preparation and refined diving technique to ensure free air flow throughout the descent. Never dive when congested, as the risk of injury far outweighs the benefit of the dive. Divers should begin equalizing their ears at the surface and repeat the action gently every few feet of descent, before any feeling of pressure is perceived.
Maintaining a slow descent rate, ideally no faster than 30 feet per minute, provides the body with enough time to manage pressure changes effectively. Staying well-hydrated and avoiding tobacco and alcohol before a dive helps minimize mucus production and inflammation. If equalization is consistently difficult, explore different techniques, such as the Frenzel maneuver.