Hypovolemia from dehydration can cause a drop in blood pressure when standing. Which term describes this change?

• A. Increased heart rate
• B. Postural hypotension
• C. Hypertension
• D. Tachycardia

Answer: (B)

Postural hypotension occurs when blood pressure falls after standing, especially when volume is low from dehydration. When you stand, gravity pulls blood into the legs, and if the circulating volume is reduced, the return of blood to the heart (venous return) and the amount the heart can pump ( preload) drop. That can cause a noticeable drop in blood pressure upon standing, sometimes with dizziness or lightheadedness. The body normally tries to compensate by increasing heart rate and constricting vessels, but with hypovolemia, these mechanisms may not fully prevent the drop.

So this term describes the BP change tied to changing position. Increased heart rate is a compensatory response, not the description of the BP change itself. Tachycardia is just fast heart rate, and hypertension is high blood pressure, which don’t describe a drop in BP when standing.