decompression sickness science definition

A common disorder that affects deep-sea divers following a sudden drop in the surrounding pressure, as when ascending rapidly from a dive. When divers are underwater, the amounts of gases such as O₂, CO₂, and N₂ in their blood increase due to the increased pressure. As they ascend to the surface and the pressure decreases, the gases in their blood expand. The extra oxygen is absorbed by the body; the extra CO₂ is excreted efficiently; but nitrogen, which the body does not use, forms bubbles in the blood and tissues. These bubbles cause severe pains in the joints and chest, skin irritation, cramps, and possibly paralysis. Decompression sickness can be avoided by ascending slowly to the surface, or by spending time in a decompression chamber.