Definition for Orthostatic hypotension
From Biology Forums Dictionary
Orthostatic hypotension is the decrease in blood pressure upon moving rapidly from a stable reclining position to standing. While reclining flat, gravity is distributed equally and so is blood. When moving to a standing position, blood initially pools in the lower extremities and cardiac output drops from about 5 L/min to about 3 L/min. Arterial blood pressure then decreases.