Which of the following is a common trigger for autonomic dysreflexia?

• A. Full bladder
• B. Hypothermia
• C. Dehydration
• D. Sun exposure

Answer: (A)

Autonomic dysreflexia occurs in people with spinal cord injury above T6 when a noxious stimulus below the injury triggers an unmodulated sympathetic response. A full bladder is the most common trigger because bladder distention sends afferent signals to the spinal cord below the injury, prompting widespread vasoconstriction below the level of injury. Since the brain cannot override this reflex, blood pressure spikes rapidly, leading to symptoms like headache, sweating, flushing above the injury, and nasal congestion. Other listed factors do not typically provoke this reflex; hypothermia, dehydration, or sun exposure aren’t classic triggers for autonomic dysreflexia. The key takeaway is recognizing that bladder distention is the frequent precipitant and addressing it promptly helps prevent a dangerous spike in blood pressure.