What is autonomic dysreflexia and what triggers it?

Autonomic dysreflexia is a life-threatening condition involving uncontrolled activation of autonomic neurons, usually occurring in people with quadriplegia or other spinal cord injuries above the T6 level. It is typically triggered by a painful stimulus to the skin or an overfilled visceral organ such as the urinary bladder. Blood pressure can skyrocket to dangerous levels, potentially causing a stroke.

Autonomic dysreflexia is defined in the source as a life-threatening condition that involves uncontrolled activation of autonomic neurons. It occurs in a majority of individuals with quadriplegia and in others who have spinal cord injuries above the T6 level, usually within the first year after the injury. The usual trigger is a painful stimulus to the skin or an overfilled visceral organ, such as the urinary bladder. The resulting surge in arterial blood pressure can rise to life-threatening levels, which may rupture a blood vessel in the brain and precipitate a stroke. Symptoms include headache, flushed face, sweating above the level of the injury, and cold, clammy skin below that level. The textbook notes that the precise mechanism of autonomic dysreflexia is not yet clear.