Variability of blood pressure response to orthostatism and reproducibility of the diagnosis of orthostatic hypotension in elderly subjects.

Background: Orthostatic hypotension (OH) is a major problem in the elderly population. Its diagnosis is based on measurement of the blood pressure (BP) response to orthostatism (BPRO). This study investigates the within-day and day-to-day variability of the BPRO and the reproducibility of the diagnosis of OH in this population.