Neurogenic orthostatic hypotension: pathophysiology and diagnosis.

Although orthostatic hypotension in elderly patients is common, neurogenic orthostatic hypotension (NOH) is a condition with substantial morbidity and a variable prognosis. Patients with severe NOH have difficulty standing for any period of time and must scrupulously avoid orthostatic stressors that exacerbate their condition. In about half of patients, supine hypertension complicates management. The diagnosis is based on measurements of supine and standing blood pressures or head-up tilt testing and is confirmed by autonomic testing. Two self-report questionnaires, the Orthostatic Hypotension Questionnaire and the Orthostatic Grading Scale, can help evaluate a patient's level of impairment, document progression, and assess the response to pharmacotherapy in clinical practice. There are many gaps in our knowledge of this rare disorder; this review summarizes what is currently known about the pathophysiology, epidemiology, prognosis, signs and symptoms, and the diagnosis of NOH.