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 high altitude, and extravehicular activity from spacecraft. [Source: Wikipedia 
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