Evaluation and treatment of orthostatic hypotension.

Orthostatic hypotension is defined as a decrease of at least 20 mm Hg in systolic blood pressure when an individual moves from a supine position to a standing position. Nonneurogenic causes of orthostatic hypotension are related to cardiac pump failure, reduced intravascular volume, venous pooling or a medication side effect. Neurogenic causes include both central and peripheral nervous system lesions. The diagnostic evaluation requires a systematic review of medications and coexisting medical conditions along with a neurologic examination to search for treatable factors that may be contributing to orthostatic hypotension. Specific testing of autonomic function is useful for detecting subclinical orthostatic hypotension or for monitoring autonomic function over a period of time. Treatment is directed at improving the patient's symptoms rather than achieving arbitrary blood pressure goals.