gas embolism, an occlusion of one or more small blood vessels, especially in the muscles, tendons, and joints, caused by expanding gas bubbles. Gas emboli can rupture tissue and blood vessels, causing decompression sickness and death. This phenomenon commonly affects deep-sea divers who rise too quickly to the surface without adequate decompression. Gas emboli are most dangerous in the central nervous system because of associated neurological changes, such as syncope, paralysis, and aphasia. Such emboli are extremely painful. The prevention and treatment of gas emboli involve gradual decompression of atmospheric gases, especially nitrogen, that are dissolved in the blood. Compare air embolism, fat embolism. See also decompression sickness.
