What is Fluid Shifts?

Translocation of body fluids. Shifts from the lower body to the upper part of the body occur under conditions of actual and simulated weightlessness and have the effect of reducing the total body water content and producing a temporary hypovolemic state. Shifts are also seen following hemodialysis and are caused by electrolyte imbalances. (From Nicogossian, Space Physiology and Medicine, 2d ed, p151)