Autonomic Dysreflexia

(AD; Hyperreflexia)


Autonomic dysreflexia (AD) is a dangerous rise in blood pressure in people with spinal cord injuries.

AD can be serious. If it is not treated right away, it can lead to seizures, stroke, and death. Treatment is aimed at finding and eliminating the problem that started the reaction.


Pain can cause an increase in blood pressure. In people with spinal lesions, pain may not be felt, but can stimulate a physical reaction. In particular, local blood vessels shrink in response to the pain which increases blood pressure. Normally, the brain will receive messages about the increase in blood pressure and take steps to lower the blood pressure back to normal. With AD, the message cannot reach the brain because of the spinal injury. As a result, the blood pressure continues to rise to dangerous levels.

AD can be caused by anything that would have been painful or physically uncomfortable before your spinal cord injury. The pain stimulation most often associated with AD is an overfull bladder. A blockage in your catheter, an infection, bladder spasms, or stones can all create pain stimulation.

Other factors that may cause pain stimulation include:

Risk Factors

AD occurs more often in people who have spinal cord injuries at the level of T6 and above (upper back). It is also more common in people with recent spinal cord injuries.

Parts of the Spine

si1936_parts of spine
AD occurs in the thoracic area of people with spinal cord injuries.
Copyright © Nucleus Medical Media, Inc.


Symptoms may not occur. In those that have them, symptoms may include:

  • Pounding headache—caused by the rise in blood pressure
  • Sweating above the level of the spinal cord injury
  • Nasal congestion
  • Blurry vision
  • Blotchy skin above the level of spinal cord injury
  • Feeling restless
  • Flushed (reddened) face
  • Chest tightness
  • Nausea
  • Goose bumps below the level of spinal cord injury
  • Cold, clammy skin below the level of spinal cord injury


AD is suspected when:

  • The symptoms above are present
  • When blood pressure is elevated in someone with a spinal cord injury at the T6 level and above


AD is treated by addressing the problem causing it. Steps to take at home include:

  • Sit upright to lower your blood pressure.
  • Elevate your head and lower your legs if possible.
  • Take frequent blood pressure checks until the episode is over.
  • Loosen or remove any clothes, shoes, leg braces, external catheter tape, or straps.
  • Look for possible causes:
    • Check your bladder. An overfull bladder is one of the most common causes of AD.
    • If you think your bowels may be a cause, do a bowel program if you can. If AD is happening during a bowel program, stop the procedure. You can start again after your symptoms go away.
    • Look for signs of injury like a pressure sore, burn, or broken bones.

After the problem has been addressed:

  • You should stay in an upright position.
  • Have your blood pressure checked frequently until you are feeling normal.

If you cannot find a cause or if symptoms are continuing or getting worse, call for medical help right away. Medical care may include blood pressure lowering medication and monitoring.

If you have a spinal cord injury, carry an AD medical alert card with you. This can alert people you are with if you have symptoms of AD and what steps to take.


Preventing AD is important. If you have an indwelling urinary catheter, take these steps to prevent problems that could lead to AD:

  • Check your tubing to make sure it is free of kinks.
  • Empty the drainage bags regularly.
  • Make sure the drainage bag is at a level lower than your bladder.
  • Check the catheter daily for signs of wear or problems with any piece of the catheter.

Other steps you can take to prevent AD include:

  • Empty your bowels regularly.
  • Avoid tight or restrictive clothing.
  • Check your skin regularly for signs of wounds or pressure sores.
  • Avoid things that could burn or damage your skin, such as sun exposure or extremely hot water.
  • Follow up with your medical team regularly to monitor your condition.


National Institutes of Arthritis and Musculoskeletal and Skin Diseases
Paralyzed Veterans of America


Canadian Orthopaedic Association
Spinal Cord Injury Canada


Autonomic dysreflexia. The National Spinal Cord Injury Association website. Available at:
...(Click grey area to select URL)
Accessed November 10, 2017.
Eldahan KC, Rabchevsky AG. Autonomic dysreflexia after spinal cord injury: systemic pathophysiology and methods of management. Auton Neurosci. 2017; S1566-0702(17)30113-3
Spinal cord injury—chronic management. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated September 7, 2017. Accessed November 10, 2017.
Last reviewed November 2018 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated: 12/20/2014

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