What is autonomic dysreflexia and when does it occur?

• A. Severe hypertension with sweating and flushing above a spinal lesion, triggered by noxious stimuli in injuries above T6
• B. Hypotension and bradycardia below a spinal lesion
• C. Normal vital signs
• D. Not related to spinal injury

Answer: (A)

Autonomic dysreflexia is an abrupt, life‑threatening rise in blood pressure caused by an unregulated sympathetic response to a noxious stimulus below a spinal cord lesion. After a injury at or above the T6 level, the brain cannot properly modulate the reflexes below the injury, so a stimulus such as bladder distension or a bowel impaction triggers widespread vasoconstriction below the lesion. The result is severe hypertension, while above the level you often see sweating and flushing as the parasympathetic system tries to compensate, though it cannot fully reverse the response below the injury. This syndrome almost always occurs with injuries at or above T6 and is commonly precipitated by triggers like a full or blocked bladder, constipation, urinary tract infection, skin irritation, or tight clothing. It is not normal vital signs, and it is clearly related to spinal injury.