micturition syncope [L, micturire, to urinate; Gk, syn, together, koptein, to cut] , a temporary loss of consciousness that tends to affect some adult males after arising from a reclining posture to urinate in an upright posture. The effect is caused by a brief interruption of blood flow to the brain and is often associated with the use of alcohol, which contributes to vasodilation. See also hypotension, orthostatic hypotension.