When I first heard the words “orthostatic intolerance” I had no clue what they meant. Orthostatic intolerance is when a person has problems with lightheadedness when rising to a standing position or when standing. This is very common in people with ME/CFS, Fibromyalgia and related conditions.
According to this article, orthostatic intolerance involves a problem with the bodys automatic regulation of blood pressure/heart rate, and is an umbrella term that takes in a group of dysfunctions with many possible symptoms, variously referred to as postural hypotension, autonomic dysfunction, orthostatic dysfunction, dysautonomia, familial dysautonomia, postural tachychardia syndrome (POTS), and more.
How orthastatic intolerance is diagnosed by tilt table testing.
Immunesupport.com offers these websites as great resources for orthostatic intolerance: