What is a common trigger for autonomic dysreflexia in patients with spinal cord injury?

• A. Bladder distention
• B. Hunger
• C. Cold environment
• D. Low blood pressure

Answer: (A)

Autonomic dysreflexia starts when a noxious stimulus below a spinal cord injury triggers an unchecked sympathetic reflex. The bladder is the most common source because distention or retention sends strong signals to the spinal cord, and with a high-level injury those signals can’t be dampened by brain input. That leads to widespread vasoconstriction below the injury and a sudden rise in blood pressure. The brain tries to respond with parasympathetic signals above the injury, which can cause headaches, sweating, or flushing, but the reflex below the injury remains unregulated, so the hypertension persists. Hunger doesn’t produce the same visceral afferent pattern, a cold environment isn’t the classic trigger, and low blood pressure wouldn’t trigger this reflex (it’s a hypertensive emergency). Since bladder distention is a readily addressable and most common trigger, it’s the best answer.