Written by DAN Staff
Ear injuries make up the overwhelming majority of medical complaints from divers. It makes sense because we put our ears through a lot of stress in a dive, and that especially applies to professionals who are up and down, and in and out of the water all day long.
In the first metre/three feet of a descent your ears experience 10 percent greater pressure than they did at the surface. At two metres/six feet that percentage doubles, and at four metres/10 feet there is enough pressure to rupture ear drums, burst blood vessels and draw fluid into our inner ears. Despite this, many divers equalize their ears as an afterthought, or forget to equalize as they try to keep up with others divers while descending.
Ear injuries can occur quickly and without notice, but by firmly establishing the importance of equalization early and often during training, you can help your student divers avoid trouble. Let’s review the most common ear injuries, so you can give your students an “earful” of good information.
A rupture of the tympanic membrane, or eardrum, is generally the result of a failure to equalize the middle ear, or a too-forceful Valsalva maneuver. The condition often presents with pain, although the rupture may relieve the feeling of pressure on the ear. Vertigo may follow. Most perforations will heal spontaneously within a few weeks, although some cases may require surgical repair. Factors like congestion, inadequate training, and excessive descent rates can increase a diver’s risk of eardrum perforation.
Like an eardrum perforation, inner-ear barotrauma can be caused by a failure to equalize, or an inappropriately aggressive Valsalva maneuver. A significant differential between external and middle-ear pressure can cause an outward bulging of the round window of the ear, which can cause inner-ear injuries without a rupture. Should the round window rupture, the loss of fluid in the inner ear can lead to damage of the hearing and balance organs, and surgical repair may be required. Divers with inner-ear barotrauma often experience severe vertigo, hearing loss, tinnitus, a feeling of fullness in their ear, and involuntary eye movements known as nystagmus.
A middle-ear barotrauma is a condition in which pressure in the tympanic cavity (the air-filled space in the middle ear) is significantly lower than the pressure outside of the ear, resulting in a relative vacuum that causes the eardrum to bulge inward, the tissue of the ear to swell, and the fluid and blood from ruptured vessels to leak into the tympanic cavity. This can be caused by a failure to equalize or an obstruction of the Eustachian tubes on descent. Divers with middle-ear barotrauma will generally report initial discomfort that may intensify to severe pain and the feeling of clogged or stuffy ears.
Facial baroparesis is the reversible paralysis of the facial nerve due to increased pressure in the middle-ear, which in some individuals can stop circulation to a facial nerve that is located close to the ear. This can happen while flying or diving, and symptoms usually include numbness, tingling, weakness,and paralysis of the face. Facial droop can sometimes be seen and cause concern, but facial baroparesis often resolves spontaneously. Divers who exhibit symptoms of facial baroparesis should seek medical attention to rule out other serious conditions.