What does it mean when your heart rate spikes after standing up?

What does it mean when your heart rate spikes after standing up?

1. Introduction Experiencing a rapid and sustained increase in heart rate immediately upon moving from a seated or lying position to a standing posture is a hallmark sign of orthostatic intolerance. This clinical phenomenon occurs when the body’s autonomic nervous system fails to properly adjust cardiovascular hemodynamics against the force of gravity. A sudden spike … Read more