What is a typical orthostatic change associated with eating disorders?

• A. No change in vital signs when standing
• B. Increase in systolic BP by more than 20 mmHg when standing
• C. Increase in pulse by more than 20 bpm when standing
• D. Decrease in pulse by more than 20 bpm when standing

Answer: (C)

Orthostatic changes describe how the body responds when moving from lying down to standing. In eating disorders, especially with dehydration and reduced circulating volume, standing causes blood to pool in the legs. The body compensates by increasing the heart rate to maintain blood flow to the brain. A rise in pulse by more than 20 beats per minute when standing is a classic sign of orthostatic tachycardia in these patients. An increase in systolic blood pressure on standing isn’t typical, and a decrease in pulse would not reflect the necessary compensatory mechanism. So the expected finding is a marked increase in heart rate upon standing.