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Also called syncope, transient loss or diminution of consciousness associated with an abrupt fall in blood pressure. In the upright position, head and brain are dependent on a certain blood pressure to maintain blood circulation through them; if the pressure falls for any reason, inadequate flow causes consciousness to recede, often with the sense of things becoming more distant. The body goes limp and falls, so that, unless artificially supported, the effect of gravity on blood flow is lost and consciousness is rapidly regained. Fainting may result from sudden emotional shock in susceptible individuals, hemorrhage, anemia), or occur with transient rhythm disorders of the heart (see arrhythmias).

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