Orthostatic intolerance and chronic fatigue syndrome--possible related conditions.

The connection between orthostatic intolerance and chronic fatigue syndrome was first introduced in 1995. It was demonstrated that many patients with chronic fatigue syndrome also had some form of orthostatic intolerance. Some studies suggested that dysautonomia may be the common problem in patients with these syndromes. Although these conditions affect an important number of people, especially younger adults, orthostatic intolerance and chronic fatigue syndrome are among the least understood of the autonomic disorders and sustained research is focused particularly on elucidating their pathogenesis and identifying the most effective methods of treatment.