What is Autonomic Dysreflexia?

Autonomic dysreflexia is a secondary condition that results from a high-level spinal cord injury (the 6th thoracic vertebrae or higher). It is sometimes also known as autonomic hyperreflexia or dysautonomia.

Autonomic dysreflexia (AD) can be very scary and confusing for the person experiencing it. The person's body starts having unusual sometimes very sudden and severe symptoms that seem to come out of nowhere.

Most often the cause of autonomic dysreflexia will be discovered and the symptoms alleviated but if left unresolved, AD can be life-threatening. For this reason, it is very important to be well educated about autonomic dysreflexia, symptoms, signs, and common triggers.


Understanding Autonomic Dysreflexia

When the spinal cord is injured above the T6 vertebrae the autonomic nervous system within the body is damaged.

This part of our nervous system controls involuntary (or automatic) things that you don't have to think about doing such as breathing, regulating body temperature, heart rate, digestion, blood pressure, and bladder, bowel, and sexual function.

Nerves out in your body send a message to the spinal cord when an uncomfortable or painful stimulus occurs below the level of spinal cord injury (SCI).  The spinal cord nerves try to bring that message of pain to the brain but are not able to; the message is blocked at the level of injury.

When your body is experiencing pain but that message cannot get to the brain, your body does not respond normally. The sympathetic portion of your autonomic nervous system is activated and its activity increases. This activity causes a narrowing of blood vessels which then causes a rise in blood pressure.

The rise in blood pressure activates nerve receptors in the blood vessels and heart, sending a message to the brain. The brain in turn sends a message to the heart, decreasing your heartbeat and dilating blood vessels above the level of injury. But, since messages are blocked at the site of injury the brain cannot send messages down throughout the body to regulate blood pressure.

The brain's inability to regulate causes your body to get incredibly confused and I would say, even frantic.

To put autonomic dysreflexia more simply ... When your body is in pain but cannot get that message to the brain, your body kinda freaks out. Your body does some crazy not-normal things to get your attention so you can fix the problem and help it feel better fast. 

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woman sweating with autonomic dysreflexia

What is Your Normal Blood Pressure?

It is important to know what your baseline blood pressure and heartbeat are on a regular basis.

To determine this, purchase a blood pressure monitor from your local store; they can be found just about anywhere. If you're an Internet shopper like I am, here's a link to Amazon where there are many highly rated blood pressure monitors:

Take your blood pressure daily on a regular basis until you are comfortable that you know what your normal blood pressure range is. I would recommend checking your blood pressure and heartbeat at least once a day for a month to determine your baseline.

Why is AD a Deadly Serious Matter?

Autonomic dysreflexia raises blood pressure. If the noxious stimulus causing the rise in blood pressure (and other symptoms) is not found and corrected the blood pressure can continue to rise.

Blood pressure can get dangerously high to the point of causing a stroke or if left completely unattended could even cause death.

Most sources say dangerously high blood pressure is over 200 mmHg. While this is definitely true, I believe a dangerously high blood pressure will differ depending on what your baseline blood pressure is, as does Craig Hospital.

A pressure increase of just 15-20 points above your normal is enough to cause an artery or vein to burst – this is called a stroke and can result in permanent body or brain damage or even death! That’s why it’s so important that you know what your normal blood pressure is and to tell your doctor when it is high for you.                                                 Craighospital.org

It is extremely important to find the cause of your autonomic dysreflexia so your body can return to its normal baseline blood pressure. If the cause cannot be discovered and your blood pressure continues to rise to a dangerous level, get to the emergency room!

Symptoms of Autonomic Dysreflexia

In addition to a rise in blood pressure, autonomic dysreflexia can have several other symptoms including:

  • a throbbing, pounding headache
  • abnormal and/or profuse sweating above the level of injury, particularly the forehead and face
  • flushed or blotchy skin, particularly the face, neck, and shoulders
  • changes in vision such as blurriness, seeing spots, or loss of vision
  • nasal congestion
  • lightheadedness
  • slower than normal heartbeat
  • anxiety
  • apprehension
  • cognitive impairment
  • difficulty breathing
  • fast or abnormal heartbeat
  • goosebumps or chills below the level of injury
  • nausea
  • increased spasms
  • stroke
  • seizures
  • death

Symptoms of autonomic dysreflexia will differ for each person and sometimes differ based on the situation.

When I get mild AD I sweat above my level of injury and feel exceptionally cold at the same time. As it progresses or if it comes on very strongly and suddenly, a throbbing headache will quickly appear along with mild cognitive impairment. This is normally all accompanied by some anxiety and a general sense of feeling very "off".

Causes of Autonomic Dysreflexia

Autonomic dysreflexia can be caused by any unpleasant or painful stimulus affecting the body.

The most common causes are bowel, bladder, and skin issues.


Bladder issues that could cause autonomic dysreflexia to include:

  • a kinked or blocked catheter tube preventing urine from passing
  • a catheter bag or tube that is somehow defective or not attached properly
  • a urine bag that is full to capacity
  • incomplete emptying of the bladder (if intermittent cathing)
  • a urinary tract infection (UTI) - also called a bladder infection
  • kidney or bladder stones


Bowel complications that can cause autonomic dysreflexia are:

  • incomplete emptying of the bowels
  • needing to have a bowel movement
  • constipation
  • impaction
  • bloating and gas
  • intestinal cramps
  • bowel infection


Skin issues that can cause autonomic dysreflexia to include:

  • pressure sores
  • burns
  • blisters
  • ingrown toenails
  • cuts and scrapes
  • insect bites
  • restrictive/constricted clothing
  • hard or sharp objects pressing on the skin
  • improperly inflated seat cushion (butt bones pressing on the base of your chair)
  • constriction or uncomfortable placement of genitalia

These lists are obviously not all-inclusive. Other issues can cause autonomic dysreflexia as well such as sexual stimulation, hemorrhoids, etc.


What to do When You Have Autonomic Dysreflexia

If you start experiencing some of the symptoms of autonomic dysreflexia it is important to find the cause as soon as possible.

It is recommended that you sit up as much as you can. Sitting up helps the blood go to your lower extremities which can lower your blood pressure.

After sitting up, start checking for anything that could be irritating your body.

Since bladder is a top cause of autonomic dysreflexia checking your catheter tube for any kinks or blockages is a great way to start. Make sure your catheter bag is not for the capacity or if you intermittent cath, try to urinate.

If your urine is cloudy, has clumps, and/or a strong odor you may have a urinary tract infection which can cause autonomic dysreflexia

If you're able to tell when you need to have a bowel movement and you think that might be the problem, then get yourself to the toilet!

Check your skin from the top to the bottom for any bumps, bruises, cuts, swelling, etc. that could be indicative of an injury.

Check your clothing to make sure nothing is binding or pinching any body parts.

My Routine

I have been injured for over 10 years and have a routine that I go through when I start experiencing autonomic dysreflexia. First, we check my catheter tube from top to bottom for kinks or blockages; being sure to check the top of the catheter bag for folds that could prevent urine from entering it. From there we take my shoes off to assure my toes aren't curled up strangely. We rearrange my bra to make sure my boobs aren't uncomfortable and we check all my other clothing to make sure there are no folds, pinching or binding anywhere (especially the crotch area). If none of that helps that I normally take some gas medicine and if that doesn't work then I move on and take a couple of ibuprofen.

Understanding Your Body

It will take a while after a spinal cord injury to understand your body and how it reacts to pain and discomfort. Over time you will begin to understand your body's new way of telling you it is uncomfortable or in pain.

It is important to always pay attention to symptoms that may indicate you are experiencing autonomic dysreflexia.

Each person may experience different symptoms of autonomic dysreflexia or different situations may bring about different symptoms.

If you are unable to find the cause of your AD and your symptoms continue to worsen it is important to get to your doctor, clinic, or the emergency room. Doctors have medicine they can give you to lower your blood pressure if needed.

Download a free wallet card with vital information about autonomic dysreflexia at the Christopher and Dana Reeve Foundation webpage by clicking the button below.

Have you experienced autonomic dysreflexia?

Have any tips and pointers for others?

Please leave your thoughts and stories in the comments section below.