The Bottom Line:
Most subjects with significant orthostatic hypotension reach a minimal blood pressure within 2 minutes of standing.
The first measurement is commonly taken after a few minutes of supine rest to establish a stable baseline. When the subject is erect, a second measurement is taken. Ideally, the second measurement should be timed, based on the accepted normal nadir of standing blood pressure. Information available regarding this normal response appears to be dependent on the measurement technique used and the frequency of measurements. Use of a sphygmomanometer, the standard technique used in studies, provides a discontinuous measurement. Accuracy could be improved with intraarterial monitoring, though it is rarely used because of its invasive nature. One investigation reported the lowest blood pressure occurs after 1 minute of standing, though the first measurement was taken at 1 minute. Other studies have shown greatest decline as early as 30 seconds. Symptomatic orthostatic hypotension may be delayed for as long as 30 minutes in some individuals, suggesting that repeated measurements may be necessary