Diving disorders

Diving disorders, or diving related medical conditions, are conditions associated with underwater diving, and include both conditions unique to underwater diving, and those that also occur during other activities. This second group further divides into conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure, and a range of conditions caused by general environment and equipment associated with diving activities.

Many diving accidents or illnesses are related to the effect of pressure on gases in the body;

Barotrauma is physical injury to body tissues caused by a difference in pressure between a gas space inside or in contact with the body, and the surroundings .

Barotrauma occurs when the difference in pressure between the surroundings and the gas space makes the gas expand in volume, distorting adjacent tissues enough to rupture cells or damage tissue by deformation. A special case, where pressure in tissue is reduced to the level that causes dissolved gas to come out of solution as bubbles, is called decompression sickness, the bends, or caisson disease.

Several organs are susceptible to barotrauma, however the cause is well understood and procedures for avoidance are clear. Nevertheless, barotrauma occurs and can be life-threatening, and procedures for first aid and further treatment are an important part of diving medicine.

Compression arthralgia is pain in the joints caused by exposure to high ambient pressure at a relatively high rate of compression, experienced by underwater divers. Also referred to in the US Navy Diving Manual as compression pains. Fast compression (descent) may produce symptoms as shallow as 30 msw. At depths beyond 180m even very slow compression may produce symptoms. The pain may be sufficiently severe to limit the diver's capacity for work, and may also limit travel rate and depth of downward excursions by saturation divers. The symptoms generally resolve during decompression and require no further treatment.

Decompression sickness is a condition caused by dissolved gases coming out of solution as bubbles in the tissues and fluids of the body during and directly after depressurisation. DCS is best known as a hazard of underwater diving but may occur in other decompression events such as caisson work, flying in unpressurised aircraft, and extra-vehicular activity from spacecraft. Since bubbles can form in any part of the body,or migrate via the bloodsteam to any part of the body, DCS can produce a wide range of symptoms, and its effects may vary from joint pain and skin rashes to paralysis and death.

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