Divers who experience difficulty equalizing risk serious injuries to their ears.

Middle-Ear Barotrauma or Reverse Squeeze

What It Is: It is the most common ear injury. Pressure must be released from your middle ear as you ascend, or the expanding air will bulge and possibly break your eardrums.
What You Feel: Pressure, then pain, which can be intense.
What to Do: Stop your ascent. Try the equalizing techniques you use when you descend. Ascend slowly; the last 30 feet can be the most difficult and painful.

Inner-Ear Barotrauma

What It Is: When you fail to equalize your middle ears, you can injure delicate inner-ear structures like the cochlea and the vestibular canals — and the damage can be permanent.
What You Feel: Deafness, tinnitus (a ringing or hissing in your ears) and possible vertigo, accompanied by nausea.
What to Do: Abort the dive and see an ear, nose and throat specialist as soon as possible.

Outer-Ear Barotrauma

What It Is: If your ear canal is blocked by a tight hood, a glob of wax or a nonvented earplug, it becomes another dead-air space that you can’t equalize when you descend. Your eardrum bulges outward, and increasing pressure in the surrounding tissues fills the canal with blood and fluid.
What You Feel: Similar to middle-ear barotrauma, including pain.
What to Do: Keep your outer ear clear.

*Adapted from DAN’s The Diver’s Complete Guide to the Ear. It’s available to download at dan.org.

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