Clinical disorders of the autonomic nervous system associated with orthostatic intolerance: an overview of classification, clinical evaluation, and management.

The disorders of autonomic control associated with orthostatic intolerance are a diverse group of infirmities that can result in syncope and near syncope (as well as a host of other complaints). A basic understanding of these disorders is essential to both diagnosis and proper treatment. These infirmities are not new, what has changed is our ability to recognize them. It has been said that "the world undergoes change in the human consciousness. As this consciousness changes, so does the world." On going studies will continue to help better define the broad spectrum of these disorders, and to elaborate better diagnostic and treatment modalities.