Which statement best defines orthostatic hypotension in terms of blood pressure changes?

• A. SBP drop ≥20 mmHg or DBP drop ≥10 mmHg upon standing
• B. SBP rise ≥20 mmHg upon standing
• C. No change in BP with standing
• D. HR increases without BP change

Answer: (A)

When you stand, gravity pulls blood toward the legs and the body must quickly tighten vessels and raise heart rate to keep brain blood flow steady. Orthostatic hypotension happens when this adjustment is inadequate, causing a noticeable drop in blood pressure soon after standing.

The best definition is a fall in systolic blood pressure of at least 20 mmHg or a fall in diastolic blood pressure of at least 10 mmHg within a few minutes of standing. This threshold captures the clinically meaningful decrease that can lead to dizziness or fainting.

Other scenarios don’t fit: a rise in systolic pressure on standing isn’t hypotension; no change in blood pressure isn’t hypotension; an increase in heart rate without a drop in blood pressure doesn’t meet the diagnostic criterion for orthostatic hypotension.