A complication of spinal cord injury where a particular stimulus can trigger an excessive response from the autonomic nervous system which causes blood pressure to rise – sometimes to dangerous levels. Stimuli that can trigger the response include bladder irritation, bowel irritation (e.g. due to constipation, gas, enema), skin irritation (e.g. due to burns, pressure sores, ingrown toenails), broken bones, tight clothing, labour and temperature extremes. The severity and frequency of the condition is highly variable. The condition occurs in patients with tetraplegia or with loss of sensation above the lower rib cage. See also Autonomic Dysreflexia