# Autonomic Dysreflexia --- **Autonomic dysreflexia** or **AD** is a runaway [[autonomic nervous system|autonomic nervous]] response that can occur in people who have a history of a [[spinal cord injury]] at or above the T6 level. As many as 90% of people with a cervical spine or high-thoracic SCI are at risk for AD. It is characterized by a very high increase in [[blood pressure]] with an accompanying *decrease* in heart rate. It is a [[medical emergency]] which left untreated can result in stroke, seizure or death. Patients with AD don't live in a state of high blood pressure, but rather experience AD episodes when certain noxious stimuli (such as a full bladder or uncomfortable clothing) are detected by the nervous system. The nerves try to signal to the brain that something is wrong but the injury prevents these signals from reaching the brain, and they also get to work automatically triggering vasoconstriction below the site of the injury, which spikes one's blood pressure. The brain *does* detect the increase in blood pressure, and works to equalize that, lowering the heart rate...which triggers vaso*dilation* above the site of the injury. It tries to send signals to stop the vasoconstriction, but the injury prevents it...and thus the BP just continues to skyrocket. ## Signs & Symptoms The signs and symptoms of autonomic dysreflexia are: - high blood pressure - low heart rate - comes from an overcorrection from the parasympathetic system - diaphoresis - severe headache - nasal congestion ## Triggers Anything "noxious stimuli" to the lower part of the body can trigger AD. Typically this includes: - a full bladder - constipation - uncomfortable clothing/wrinkled sheets - something pressing into the legs/torso ## Treatment Treatment for autonomic dysreflexia primarily consists of removing the noxious stimuli that triggered the reflex in the first place. If that doesn't resolve it a short acting [[antihypertensive]] like hydralazine can be given. ___