What Is It? Decompression sickness, also called generalized
barotrauma or the bends, refers to injuries caused by a rapid
decrease in the pressure that surrounds you, of either air or
water. It occurs most commonly in scuba or deep-sea divers,
although it also can occur during high-altitude or unpressurized
air travel. However, decompression sickness is rare in
pressurized aircraft, such as those used for commercial flights.
When you scuba dive with compressed air, you take in extra
oxygen and nitrogen. Your body uses the oxygen, but the nitrogen
is dissolved into your blood, where it remains during your dive.
As you swim back toward the surface after a deep dive, the water
pressure around you decreases. If this transition occurs too
quickly, the nitrogen does not have time to clear from your
blood. Instead, it separates out of your blood and forms bubbles
in your tissues or blood. It is these nitrogen bubbles that
cause decompression sickness. The condition is called the bends
because joint pain, a common sy