History of decompression research and development gets too high when compared to the ambient pressure. These bubbles, and products of injury caused by the bubbles, can cause damage to tissues known as "decompression sickness" or "the bends". The immediate goal of controlled decompression is to avoid development of symptoms of bubble formation in the tissues of the diver, and the long-term goal is to also avoid complications due to sub-clinical decompression injury. The symptoms of decompression sickness are known to be caused by damage resulting from the formation and growth of bubbles of inert gas within the tissues and by blockage of arterial blood supply to
Decompression equipment during in water decompression for scuba divers, but can be up to 1.9 bar in-water and 2.2 bar in the chamber when using the US Navy tables for surface decompression, and up to 2.8 bar for therapeutic decompression. Open circuit scuba divers by definition are independent of surface supply, and must take any gas mixture with them that is to be used on the dive. However, if they are confident of returning by a specific route, the decompression gas may be stored at appropriate places on that route. The cylinders used for this purpose are called stage cylinders, and they