Decompression sickness, caused when a moves from a high-pressure environment to one of low pressure too rapidly, The Bends is an illness that arises from the rapid release of nitrogen gas from the bloodstream and is caused by bubbles forming in the blood when a diver ascends to the surface of the ocean to rapidly. It is also referred to as Caisson sickness, decompression sickness (DCS), and Divers' Disease.