condition in which there is a deviation from or interruption of the normal structure or function of the parasympathetic or sympathetic divisions of the autonomic nervous system; autonomic dysfunction may be associated with hypothalamic diseases, brain stem disorders, spinal cord diseases, and peripheral nervous system diseases; manifestations include impairments of vegetative functions including the maintenance of blood pressure, heart rate, pupil function, sweating, reproductive and urinary physiology, and digestion.