What is the bends also called?

Answer 1

Nitrogen from a diver's air tank increases in pressure as a diver descends. For every 33 feet in ocean water, the pressure due to nitrogen goes up another 11.6 pounds per square inch. As the pressure due to nitrogen increases, more nitrogen dissolves into the tissues. The longer a diver remains at depth, the more nitrogen dissolves for any specific depth. Nitrogen gas is not utilized by the body and builds up over time in body tissues. If a diver surfaces too fast, the excess nitrogen will come out rapidly as gas bubbles. Depending on which organs are involved, these bubbles produce the symptoms of decompression sickness. The process is similar to shaking a can of carbonated soda. If the pressure is high enough, the carbon dioxide in the soft drink will emerge out opening of the can as a gush of bubbles. The bends are joint pains involving the arms or legs. Intensity varies from mild to severe. Arms are more commonly involved than legs. The pain is most prominent around joints and in the upper shoulder area. It is sometimes relieved by direct pressure. This occurs because nitrogen is released into the joints and muscles.

Addition

A small change is that the pressure inside a suba cylinder does not change depending upon depth as it is nonflexible container. However, the parital pressures of the gases breathed due change once they exit the cylinder (i.e. are breathed).

DCS is caused from the gas a diver absorbs during a dive coming out of solution in a divers tissue and thus bubbling. These bubbles push on nerves in the body causing pain as well as an injury. The two common types of DCS are know as Type I (pain only bends) and Type II (central nervious system bends). It is likely a diver will develop both. DCS is occurs due to excessive gas in the body bubbling and exceeding the bodies capacity to deal with the bubbles.

Answer 2

Decompression sickness