Orthostatic hypotension is precipitated by standing and is associated with hypotension and tachycardia due to what mechanism described in the material?

Orthostatic hypotension is precipitated by standing and is associated with hypotension and tachycardia due to what mechanism described in the material?

• A. On standing, blood pressure rises and heart rate falls
• B. Precipitated by sitting; volume overload
• C. Precipitated by standing; hypotension and tachycardia due to volume depletion
• D. Associated with fever and chest pain

Answer: (C)

Orthostatic hypotension is about the body's failure to maintain blood pressure when moving from lying to standing. When you stand, gravity pulls blood into the leg and abdominal veins, reducing venous return to the heart. This drop in preload lowers stroke volume and cardiac output, so blood pressure falls. The body tries to compensate with the baroreceptor reflex, increasing sympathetic activity and heart rate (tachycardia) to maintain perfusion. If someone is volume depleted, there isn’t enough circulating fluid to begin with, so the drop in venous return is greater and the compensatory response may be inadequate, producing marked hypotension plus tachycardia. This is exactly described by standing precipitating hypotension with tachycardia due to volume depletion. The other options don’t fit because they describe the wrong posture effect, wrong volume status, or unrelated symptoms.

Orthostatic hypotension is about the body's failure to maintain blood pressure when moving from lying to standing. When you stand, gravity pulls blood into the leg and abdominal veins, reducing venous return to the heart. This drop in preload lowers stroke volume and cardiac output, so blood pressure falls. The body tries to compensate with the baroreceptor reflex, increasing sympathetic activity and heart rate (tachycardia) to maintain perfusion. If someone is volume depleted, there isn’t enough circulating fluid to begin with, so the drop in venous return is greater and the compensatory response may be inadequate, producing marked hypotension plus tachycardia. This is exactly described by standing precipitating hypotension with tachycardia due to volume depletion. The other options don’t fit because they describe the wrong posture effect, wrong volume status, or unrelated symptoms.