Decompression sickness Decompression sickness Decompression sickness (DCS; also known as divers' disease, the bends, aerobullosis, or caisson disease) describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurisation. DCS most commonly refers to problems arising from underwater diving decompression (i.e., during ascent), but may be experienced in other depressurisation events such as emerging from a caisson, flying in an unpressurised aircraft at altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness. Since bubbles can form in or migrate to any part of the body, DCS
Surface-supplied diving pulmonary barotrauma (burst lung). Although some of these may occur in other settings, they are of particular concern during diving activities. Long term diving disorders include dysbaric osteonecrosis, which is associated with decompression sickness. These disorders are caused by breathing gas at the high pressures encountered at depth, and divers may breathe a gas mixture different from air to mitigate these effects. Nitrox, which contains more oxygen and less nitrogen, is commonly used as a breathing gas to reduce the risk of decompression sickness at depths to about . Helium may be added to reduce the amount of nitrogen and