Orthostatic Intolerance
Orthostatic intolerance occurs when the symptoms become worse when you are sitting upright or standing. This might make you feel dizzy, weak, or lightheaded. In some cases, you may have a few symptoms that could make you feel about to faint, such as seeing spots before the eyes or blurred vision. Keep in mind that you might experience either brain fog or this symptom to meet the diagnostic criteria for chronic fatigue syndrome. [6]
