What describes a large decrease in blood pressure upon standing?

A large decrease in blood pressure upon standing is indicative of orthostatic hypotension. This condition occurs when a person moves from a sitting or lying position to a standing position, and their blood vessels do not constrict properly, leading to a significant drop in blood pressure. This can result in symptoms such as dizziness, lightheadedness, or even fainting due to insufficient blood flow to the brain.

Orthostatic hypotension typically arises from various factors, including dehydration, certain medications, or underlying health conditions that affect the body's ability to regulate blood pressure. Understanding this illustrates the importance of recognizing and managing blood pressure changes in individuals, especially those who may be elderly or have specific health issues.

In contrast, hypertension refers to high blood pressure and does not correlate with the phenomenon of blood pressure dropping upon standing. Pneumonia is a respiratory infection and does not directly affect blood pressure changes associated with standing. Neurogenic shock is a state of reduced blood flow generally due to nervous system dysfunction, but it would present differently than the isolated blood pressure drop related to postural changes seen in orthostatic hypotension.