Middle-Ear Barotrauma on Ascent,
aka Reverse Squeeze
What happens: Pressure must be released from your middle ear as you ascend, or the expanding air will bulge and even break your eardrums. Normally, expanding air escapes down your Eustachian tubes, but if the tubes are blocked with mucus at depth (usually the result of poor equalizing on descent, diving with a cold or relying on decongestants that wear off at depth), barotrauma can result.
What you feel: Pressure, then pain. Some divers also feel vertigo from the unusual pressure on their balance mechanism.
What to do: Sometimes one of the equalizing techniques used on descent will clear your ears on ascent. Pointing the affected ear toward the bottom may help, too. Ascend as slowly as your air supply allows, remembering that the last 30 feet will be most difficult. Otherwise, you will just have to endure the pain to reach the surface.
Inner-Ear Barotrauma
What happens: Sometimes, the stresses on your middle ear—from not equalizing or from trying too hard with a Valsalva technique—damage the adjacent inner ear hearing structures (the cochlea) and balance structures (the vestibular canals), and permanent incapacity can result.
What you feel: Deafness: Hearing loss can be complete, instant and permanent, but divers usually lose just the higher frequencies. The loss becomes noticeable only after a few hours. You may not be aware of the loss until you have a hearing test.
Ringing: You may experience “tinnitus,” a ringing or hissing in your ears.
Vertigo: The sense that the world is whirling around you, often accompanied by nausea.
What to do: Abort the dive and go as soon as possible to an ear, nose and throat specialist with experience treating divers. Inner-ear injuries are tricky and require prompt, correct treatment from a specialist.
Outer-Ear Barotrauma
What happens: If your ear canal is blocked by a tight hood, a glob of wax or a non-vented ear plug, it becomes another dead air space that can’t equalize on descent. Your eardrum bulges outward, and increasing pressure in the surrounding tissues fills the canal with blood and fluid.
What it feels like: Similar to middle-ear barotrauma.
What to do: Keep your outer ear clear, which can be difficult for divers with exostoses (see pg. 94). These are hard, bony growths in the ear canal that can trap dirt and wax and even grow so big they completely block the ear canal. They are believed to be caused by repeated contact with cold water.
Prevention: Wear a hood. It will reduce the flow of water to your ears, and what does reach them will be warmer.
SERIOUS DIVING…SERIOUS FUN