Autonomic Dysreflexia, also known as Hyperreflexia, is a condition where the blood pressure in a person with a spinal cord injury (SCI) above T5-6 becomes excessivly high due to the over activity of the Autonomic Nervous System

Autonomic Dysreflexia is usually caused when a painful stimulus occures below the level of.spinal cord injury. The stimulus is then mediated through the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

The CNS is made up of the spinal cord and brain, which control voluntary acts and end organs via their respective nerves. The PNS is made up from 12 pairs of crainial nerves, spinal nerves and peripheral nerves. The PNS also is divided into the somatic nervous system and the autonomic nervous system. The autonomic nervous system is responsible for the signs and symptoms of autonomic dysreflexia. The autonomic nervous system normally maintains body homeostasis via its two branches, the parasympathetic autonomic nervous system (PANS) and the sympathetic autonomic nervous system (SANS). These branches have complementary roles through a negative-feedback system; that is, when one branch is stimulated, the other branch is suppressed.

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