Final answer:
Orthostatic hypotension is defined as a temporary drop in blood pressure upon standing and can cause dizziness or lightheadedness. It can be caused by low blood volume or by autonomic failure due to conditions like diabetes or multiple system atrophy.
Step-by-step explanation:
A temporary drop in blood pressure, related to suddenly assuming an upright position is defined as orthostatic hypotension. Orthostatic hypotension occurs when there is a drop in blood pressure due to a person standing up from a sitting or lying position, which can lead to dizziness or lightheadedness because the brain is temporarily receiving less blood, and therefore less oxygen. When someone stands up, gravity causes blood to pool in the legs, and the cardiovascular system has to adjust by increasing cardiac output to continue to supply the brain with blood. Sometimes, the sympathetic system cannot adjust quickly enough, leading to a temporary decrease in blood pressure to the brain, resulting in symptoms such as wooziness or loss of balance.There are two primary causes of orthostatic hypotension: The first one is a low blood volume, known as hypovolemia, which may result from dehydration or the use of medications affecting fluid balance. The second cause is autonomic failure, where sympathetic functions are compromised due to disorders such as diabetes or multiple system atrophy.