Technically, the word barotrauma refers to any injury resulting from a change in pressure ("baro," as in "barometer") on either side of a bodily membrane. Usually, when people talk about barotrauma in this context, they mean ear barotrauma. While more serious types of pressure-related injuries are possible throughout the body, ear barotrauma is the most common injury of this type, because of the mechanics of your ear membranes.
The eardrum is the only part of your body that depends entirely on pressure and vibrations to work -- it's also tiny, delicate and very sensitive -- which makes it a common victim of this situation. You can get into pressure trouble on airplanes, as you've probably noticed, as well as diving even just a few feet. Both cases involve tremendous changes in pressure that could affect lots of parts of your body, but in practice it's usually the ears that suffer.
The good news is that ear barotrauma usually goes away on its own after a few hours or days, as the pressure slowly equalizes. The even better news is that some simple rules -- whether you're going underwater or up in the air -- can help you cope with it, ease your recovery, or even make sure it never happens at all.
Ear barotrauma occurs when the pressure inside your ear -- on the interior side of your eardrum -- is higher than it is outside. Flying and underwater diving are the most common causes, because they're the two times most of us find ourselves dealing with pressure outside the normal range. However, if you've ever climbed or driven up a steep hill, your ears may have popped, just like when you're on a flight.
That popping sensation means your eardrum is trying to equalize those levels so the pressure is the same on both sides of the eardrum. You can avoid or ease this painful experience with the common go-to tricks, like chewing gum and yawning during your ascent, and by making sure you and your children are awake during ascent and descent to help your body make these equalizations as easily as possible. But because this is a process your body has to do for itself, there's only so much you can do.
Think about the pain of sinus pressure when you have a cold, for example. That's due to a similar problem, only instead of a sudden change in pressure outside your body, it's an internal pressure buildup due to the obstructions of mucus and inflammation. In fact, doctors recommend the same preventive treatment for ear barotrauma as this more familiar type of pressure: A decongestant, taken according to the label, throughout your flight, will help your body's equalization procedures move as quickly and efficiently as possible.
For scuba divers, it's key to your certification that you understand how barotrauma works, what it's doing to you, and how you can avoid it. Divers have a much higher danger of other types of barotrauma, because going underwater also involves a difference between the air in your lungs and the pressure of the water outside you. If you're having lung problems -- chronic ones like asthma, or even just a cold -- you're going to have more trouble regulating that pressure.
As a diver, you're cautioned never to hold your breath, because it could cause your lungs to balloon up, essentially, which can be incredibly painful and cause real damage to your respiratory system. While pulmonary barotrauma such as this can also take place to a lesser degree, resulting in minor symptoms, it's still damaging. Remembering not to panic -- and resisting the urge to take large gulps of air -- is another part of the training, which also includes some hard-and-fast rules: Never hold your breath underwater, ascend fewer than 30 feet (9.1 meters) each minute, and always keep an eye on your air supply.
In fact, because of the weight of water and the mathematics of underwater pressure, you're in more danger -- both going down and coming up -- the closer you are to the surface. It may seem counterintuitive, but that's why it's so important to be educated: It's not about the depth, or the weight of the pressure, just the difference in pressure as it affects your membranes. There's a much steeper change in that pressure the closer you are to the surface, which means your membranes are dealing with more changes, occurring faster, as you begin your descent or finish returning to the surface.
More Severe Types of Barotrauma
For the more serious pressure-related injuries -- overfilled lungs, "the bends," or gastric barotrauma -- divers tend to exhibit dramatic symptoms immediately. If you're with someone who complains of chest pains, exhibits stroke-type symptoms, loses consciousness, or otherwise has a traumatic reaction after surfacing, you can at least suspect they're having a lung-related barotrauma and are in need of immediate aid. A U.S. Navy report showed that, in 24 cases of pulmonary barotrauma that were studied, nearly half showed symptoms within one minute of reaching the surface. Nine took place while still underwater, and four cases developed within 10 minutes of surfacing [source: Campbell].
In rare cases, or when other things like infections are also part of the problem, doctors may insert short-term tubes to help drain the fluid buildup. More holistic patients have also reported luck with candling -- a non-medical treatment in which heat is used to draw blockages out of the ear -- although reports on the safety and usefulness of this old practice vary. If you're not sure about the severity of your injury, or you're experiencing vertigo symptoms, consult a physician. It's possible that your trauma goes further into the ear than most of these injuries usually do.
For most of us, these circumstances are very unlikely compared to more common types of barotrauma. While the body is designed to deal with pressure imbalances, and will eventually equalize that pressure as well as heal any damage that's occurred, you are still better off armed with the facts. Long-term injury or hearing loss are rare in simple airplane barotraumas -- although they can be excruciating -- and most treatment involves simply waiting it out or repeating your yawning exercises to ease the sensation. Just remember to visualize what's happening when your body is about to undergo a sudden change in pressure, and be mindful of what you can do to avoid the pain. If no red-alert symptoms accompany common barotrauma, give your body a few hours to recover, and it should soon be a distant memory.
I've never lived on the coast and haven't spent a lot of time in the ocean, so I've always been fascinated by "the bends" and other kinds of pressure-related injuries. You don't really think of your body too often as a closed system, but when you start to learn the ways pressure can act on your mechanics, it opens up a whole new way to consider the precision and complexity of the engineering you use to get around all the time -- not just in the water, but every day.
- Boro, Fred MD, PhD. "Ear Barotrauma." Skin Diver.com. (June 24, 2012) http://www.skin-diver.com/departments/scubamed/EarBarotrauma.asp?theID=987
- Bove, Alfred A., MD, PhD. "Barotrauma." Merck Manuals, Apr 2009. (June 24, 2012) http://www.merckmanuals.com/professional/injuries_poisoning/injury_during_diving_or_work_in_compressed_air/barotrauma.html - v1115475
- Campbell, Ernest, MD, PhD. "Middle Ear Barotrauma." Scuba Doc, 2009. (June 24, 2012) http://scuba-doc.com/Midearbt.html
- ibid. "Pulmonary Barotrauma." Scuba Doc.com, 2010. (June 24, 2012) http://www.scuba-doc.com/pulbt.html
- Delphia, Bruce. "Common Ear Injuries While Diving." Alert Diver, Jan/Feb 1999. (June 24, 2012) http://www.diversalertnetwork.org/medical/articles/article.asp?articleid=45
- Gortoza, Jack. "Know how to Prevent the Dangers of Scuba Diving." Daily Scuba Diving.com, 24 Nov 2009. (June 24, 2012) http://www.dailyscubadiving.com/know-how-to-prevent-the-dangers-of-scuba-diving
- Hutch, Peter. "Information on Ruptured Eardrum." StreetDirectory.com, 2011. (June 24, 2012) http://www.streetdirectory.com/travel_guide/111900/ear_nose_and_throat/information_on_ruptured_eardrum.html
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- Scuba Guide, The. "Scuba Diving Risks." The Scuba Guide. (June 24, 2012) http://www.thescubaguide.com/certification/risks.aspx
- Soo Hoo, Guy W. "Barotrauma and Mechanical Ventilation." MedScape, Apr 2011. (June 24, 2012) http://emedicine.medscape.com/article/296625-overview
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