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SCI Forum Report & Video


Autonomic Dysreflexia

Presented on October 9, 2007, by Janna Friedly, MD, assistant professor in the Department of Rehabilitation Medicine at the University of Washington. Read the report or watch the video from this page.

Autonomic dysreflexia (AD) is a medical problem unique to people with spinal cord injuries (SCI). Although uncommon, it is a serious concern because it can be life threatening and needs immediate attention. If you know what you are looking for, however, it is relatively easy to recognize and treat. But since many health care providers may not be familiar with AD, it is important to understand it yourself and carry a medic alert card. Learn how to prevent, recognize and treat AD in this 35-minute video.


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Autonomic Dysreflexia
By Janna Friedly, MD


Table of Contents


Autonomic dysreflexia (AD) is a medical problem unique to people with spinal cord injuries (SCI). Although uncommon, it is a serious concern because it can be life threatening and needs immediate attention. If you know what you are looking for, however, it is relatively easy to recognize and treat. But since many health care providers may not be familiar with AD, it is important to understand it yourself and carry a medic alert card.

What is autonomic dysreflexia (AD)?

AD is an abnormal response to a problem in your body—pain, pressure, full bladder or bowel—somewhere below the level of your SCI. Because of the SCI, your body doesn't respond properly to signals that something is wrong. Instead, your body may develop a sudden rise in blood pressure, and this can lead to stroke, seizures or death.

How does AD happen?

AD is usually triggered by something that would cause pain or discomfort in a person without SCI, such as a full bladder, tight clothing or an ingrown toenail. In non-injured individuals, the body reacts to pain by narrowing the blood vessels, and this causes blood pressure to increase. Receptors near your brain and heart receive messages from non-spinal cord pathways (nerves in the sympathetic nervous system) that your blood pressure is getting too high, and your brain responds by sending signals down the spinal cord to slow down the heart beat and relax the blood vessels. As the blood vessels open up and widen, blood pressure goes back down. Meanwhile, pain signals coming through the spinal cord have told the brain there is something wrong, so the individual feels the discomfort and knows to do something about it and remove the source of the pain.

In SCI, when something causes pain or discomfort below the level of the injury, the body still responds by narrowing blood vessels and blood pressure starts to rise. And the brain still gets the message from the sympathetic nervous system that there is a problem and sends signals down the spinal cord to slow the heartbeat and open up the blood vessels. This slows your heartbeat and makes you flushed, red or blotchy above the injury, but the signals can’t get past the injury level, so the blood vessels continue to narrow below the injury and the blood pressure keeps rising. Furthermore, all this is happening without your knowing you have a problem below your injury, since the pain message couldn’t travel up your spinal cord to your brain.

Who is at risk for AD?

Some people within this risk group get AD frequently, others get it once in a while, and some don't get it at all. We don't quite understand why some people get it more than others. Furthermore, some people get mild symptoms while others get very severe symptoms. Recent research in animal models indicates that the amount of sensory nerve regrowth right at the level of the SCI may play a role, suggesting that people who have more of that growth and regeneration may be at higher risk of AD (Cameron, 2006).

Common causes of AD

  1. Bladder—the most common culprit!
    1. Overfull or distended (stretched) bladder.
    2. Kinked Foley catheter.
    3. Overfilled leg bag.
    4. Urinary tract infection.
    5. Any obstruction that keeps urine from getting out of the bladder, like a stone.
  2. Bowel
    1. Over-distension (stretching of rectum or anus) during bowel program.
    2. Constipation or impacted stool.
    3. Hemorrhoids.
    4. Anal fissures or skin breakdown.
  3. Skin irritation
    1. Prolonged pressure or pressure sore.
    2. Ingrown toenail.
    3. Sunburn.
    4. Tight clothing.
  4. Sexual activity
    1. Over-stimulation during sex—things that would be painful if you had full sensation.
  5. Gynecologic Issues in Women
    1. Menstrual cramps
    2. Labor and delivery.

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Common warning signs of AD

Warning signs vary from person to person: Some people have all of the signs, some only one or two; signs may be obvious in some and more subtle in others. So it's important for each person who is at risk of dysreflexia to get to know their own bodies and know how dysreflexia affects them.

While all these signs and symptoms are uncomfortable and can be very annoying or upsetting, the increased blood pressure is what makes this a medical emergency.

How to lower your blood pressure

  1. Fix the problem—whatever it is!
    Identify what the problem is and take care of it (see What to do if you have AD, below). If that doesn’t lower your blood pressure, go to step 2.
  2. Use blood pressure medication prescribed by your doctor, usually nitroglycerin paste applied to the surface of your skin, where it gets readily absorbed into your blood stream and brings down your blood pressure very quickly. As soon as you figure out what’s causing the problem and the dysreflexia goes away, you can just wipe it right off.

    About nitroglycerin paste:

What to do if you have AD

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  1. Sit straight up to lower your blood pressure, or elevate your head in bed and lower your legs.
  2. Quickly remove or loosen anything tight or causing pressure, such as:
    1. Abdominal binder
    2. Catheter tape, leg bag straps
    3. Elastic hose or bandages
    4. Clothes
    5. Shoes or braces
  3. Check your blood pressure every five minutes. If your blood pressure remains elevated for more than 10 minutes and you have blood pressure medicine prescribed by your doctor, take it as prescribed. Make sure you know your doctor's recommendations for how high your blood pressure needs to be before you use nitroglycerin paste or another blood pressure medicine. This is different for each person, but is often 150/90.  If you do not know, call a professional to assist you.
  4. Check your bladder.
    1. Indwelling or Foley catheter:
      1. Check catheter for kinks.
      2. Empty the drainage bag.
      3. Consider irrigating bladder with saline (only if you have experience with this; use 30 cc at most) to dislodge anything that might be blocking the inside of the Foley.
    2. Intermittent catheterization
      1. Catheterize your bladder—use lidocaine gel (an anesthetic, or numbing, gel).
      2. If catheter doesn’t pass through and you still have symptoms, call 911.
  5. If you suspect your bowels as a cause, do a bowel program if you can, but make sure to use lidocaine gel for the digital stimulation.
  6. If you follow the above suggestions and the symptoms get worse or persist —STOP and go to the emergency room.
  7. If the symptoms do go away, write down what symptoms you had and what you did to fix the problem, because oftentimes this is what is going to happen in the future. Let your healthcare provider know about the episode of AD and how you handled it, since there may be some other things that they can recommend to prevent it from happening again.
  8. If symptoms come back again, repeat the steps and call your healthcare provider or go to the emergency room.

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AD tool kit

Anyone who is at risk for dysreflexia or has had dysreflexia in the past should keep a tool kit on them at all times.

Preventing AD

As with most things in SCI, prevention is really key. Since we know what some of the triggers are for dysreflexia, it makes it easier to know what to do to prevent it.

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Key points


Autonomic Dysreflexia: What You Should Know, a consumer guide published by the Consortium for Spinal Cord Medicine and the Paralyzed Veterans of America (PVA). Download the guide for free from the PVA Web site at http://www.pva.org/site, or call the PVA Publications Distribution Center toll-free at 888-860-7244 to receive a free copy in the mail ($3 shipping charge). A wallet-size information card is included in the printed guide.


  1. Autonomic Dysreflexia: What You Should Know, consumer guide, Consortium for Spinal Cord Medicine, Paralyzed Veterans of America, Washington DC, 1997.
  2. Cameron AA, Smith GM, Randall DC, et al. Genetic manipulation of intraspinal plasticity after spinal cord injury alters the severity of autonomic dysreflexia. J Neurosci. 2006 Mar 15:26(11):2923-32.

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