. (Med.) A disease frequently induced by remaining for some time in an atmosphere of high pressure, as in caissons, diving bells, etc. It is characterized by neuralgic pains and paralytic symptoms. It is caused by the release of bubbles of gas, usually nitrogen, from bodily fluids into the blood and tissues, when a person, having been in an environment with high air pressure, moves to a lower pressure environment too rapidly for the excess dissolved gases to be released through normal breathing. It may be fatal, but can be reversed or alleviated by returning the affected person to a high air pressure, and then gradually decreasing the pressure to allow the gases to be released from the body fluids. It is a danger well known to divers. It is also called the bends and decompression sickness. It can be prevented in divers by a slow return to normal pressure, or by using a breathing mixture of oxygen combined with a gas having low solubility in water, such as helium. [ Webster 1913 Suppl. +PJC ]