Hyperventilation in Postural Hypotension

Abstract
In normal subjects hyperventilation causes a drop in arterial blood pressure, apparently because of the direct effect of hypocapnia on the peripheral vessels. In persons with disease of the autonomic nervous system, the drop in blood pressure is much greater because it is not effectively opposed by reflex vasoconstriction. Consequently, hyperventilation caused by anxiety may greatly intensify postural hypotension in such patients and contribute significantly to their disability. A pertinent case is reported.