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
Scuba set assembled as an integrated part of the set, but is not technically part of the breathing apparatus. The cylinder is usually worn on the back. "Twin sets" with two low capacity back-mounted cylinders connected by a high pressure manifold were more common in the 1960s than now for recreational diving, although larger capacity twin cylinders ("doubles") are commonly used by technical divers for increased dive duration and redundancy. At one time a firm called Submarine Products sold a sport air scuba set with three manifolded back-mounted cylinders. Cave and wreck penetration divers sometimes carry cylinders attached at their sides instead,