Diseases of the parasympathetic or sympathetic divisions of the autonomic nervous system; which has components located in the central nervous system and PERIPHERAL 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.