What is autonomic hyperreflexia?

On Behalf of | Feb 24, 2021 | Personal Injury

When spinal cord injuries are serious, they can have a wide range of side effects and complications. Depending on the extent and severity of the injuries, these effects can sometimes be life-threatening.

According to Model Systems Knowledge Translation Center, autonomic hyperreflexia is a potentially serious condition that impacts people whose spinal injury affected a specific area of the thoracic spine. Here are a few facts about the condition.

Why it happens

Your body’s sympathetic nervous system responds to any pain and stress you experience. This is what triggers “fight or flight” behaviors when threatened. Physical changes like increased heart rate, pupil dilation, and narrowing of the blood vessels occur as a result. The parasympathetic nervous system kicks in to ease these effects and induce the body to relax.

When pain is experienced below the site of your spinal cord injury, the sympathetic nervous system kicks into gear and triggers fight or flight instincts. However, signals from the parasympathetic nervous system fail to extend below the site of the injury where pain or discomfort is taking place. That means the panicked response will continue unabated.


Autonomic hyperreflexia can result from seemingly minor occurrences when you have a severe spinal cord injury. This includes painful or uncomfortable sensations affecting the skin, bowel and bladder issues, and even menstruation. It can also occur with more serious injuries, such as bone fractures.

Possible effects

Blood pressure naturally increases when your body goes into panic mode. If your body never receives the resting signals, high blood pressure will continue to be an issue until the source of the pain and discomfort is resolved. Prolonged high blood pressure is associated with a number of complications, including strokes and heart failure.

Severe spinal cord injuries are associated with many lasting effects. If your injury was caused by another person’s negligence, you may be eligible to seek compensation for medical bills and lost wages.

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