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Autonomic Dysreflexia

What is autonomic dysreflexia?

  • Autonomic dysreflexia (AD) is a condition where the body's reflexes overreact to a stimulus. AD happens most often to persons with a spinal cord injury (SCI) at the neck or upper back. AD may also occur in persons who have had spinal cord surgery, tumors of the spine, or nerve diseases. The spinal cord is a pathway for nerve impulses (messages) sent to and from the brain and body. Many reflex actions uncontrolled by the brain are also carried out by the spinal cord. A harmful stimulus is anything that may trigger or cause pain, irritation, or discomfort. AD happens when the harmful stimulus is located below the level of the SCI. This stimulus sends nerve impulses through the spinal cord, which get blocked as they reach the injury. Since these impulses do not reach the brain, the body will is not able to respond correctly.

  • An example of a stimulus is a pressure sore from sitting in one place for a long time. Normally, pain is felt from the pressure sore, and the body sends this message to the brain. The brain responds by sending a message to the body to change position. These messages travel through the spinal cord, but when there is a spinal cord injury, the messages do not get through. Instead, the body reacts with a reflex that causes blood vessels to narrow. This leads to a sudden and dangerous increase in blood pressure. The brain tries controlling the high blood pressure but cannot. This is because the message sent from the brain through the spinal cord cannot get past the spinal cord injury.

What causes autonomic dysreflexia?

Any harmful trigger below the level of SCI may cause AD. This may include problems in any of the following:

  • Bladder or kidneys: Distended (overfull) bladder, infections, stones, or procedures which may irritate the bladder and kidneys.

  • Bone: Fractures (broken bones), bone spurs, or other bone injuries.

  • Bowel: Overly distended bowels, constipation (dry, hard bowel movements), stool (bowel movement) impaction, hemorrhoids, or anal tears. Procedures, such as digital (finger) stimulation, or other conditions, including appendicitis or ulcer, may also cause AD.

  • Reproductive: Menstruation (monthly period in women), sexual activity, pregnancy, labor, and delivery (child birth).

  • Skin: Pressure sores, ingrown toenails, or infection.

What are the signs and symptoms of autonomic dysreflexia?

You may have one or more of the following:

  • Cool, pale skin with goose bumps and increased spasms (twitching) below your SCI.

  • Nasal congestion (stuffy nose), blurred vision (sight), or flushed (red), sweaty skin above the level of SCI.

  • Nausea (feeling sick to your stomach).

  • Nervousness or anxiety.

  • Severe, pounding headache.

  • Slow or fast heartbeat.

  • Sudden increase in blood pressure.

  • Tightness in chest.

How is autonomic dysreflexia diagnosed?

There are no tests that can be done to diagnose AD. Caregivers will be able to diagnose it by your signs and symptoms. Caregivers may also check for other possible causes of your signs and symptoms. Your caregiver may do a cystometrogram. This test measures the way your bladder contracts when it fills and empties. Caregivers will pay close attention to your blood pressure and pulse while your bladder is filling during this test. Blood and urine tests, computerized tomography (CT) scan, or magnetic resonance imaging (MRI) test may also be needed. These may help caregivers rule out other conditions or diseases that may cause or look like AD.

How is autonomic dysreflexia treated?

Treatment of AD should be started as soon as you have signs and symptoms. Treatment may include any of the following:

  • First aid: You may need to sit up or lie with your head raised to help decrease blood pressure. Your clothes may need to be loosened, and any tight wrappings, such as belts or straps, removed. Your blood pressure should be checked and taken every 2 to 5 minutes.

  • Correcting the cause: Any underlying condition or disease that is causing the symptoms needs to be treated.

    • Catheterization: Caregivers will check for problems in your bladder. If you have a catheter in place, your caregiver will check your catheter, connecting tube, and bag. If a kink or block is found or your urine is not draining, your caregiver may need to change your catheter. If you do not have a catheter in place, your caregiver will feel your lower abdomen (stomach). A catheter may be placed if your bladder is full.

    • Fecal removal: Caregivers may check for fecal (stool) obstruction if there was no problem found in the bladder. Using a gloved finger with a lubricating jelly, your caregiver will check for stool in your rectum (rear-end). Your caregiver will gently remove the stool to see if this eases your symptoms.

  • Blood pressure medicine: This medicine may be given to decrease your blood pressure. You may need this if the cause of AD is not found and your blood pressure stays high.

  • Other: Caregivers may look for other problems if bladder distention or bowel obstruction is not the cause of AD. Infections, bed sores, or other possible causes are checked. Antibiotic medicine may be given if you have an infection. You may need to stay in the hospital so caregivers can do more tests or watch you more closely.

How can autonomic dysreflexia be prevented?

The most common causes of AD are bladder, kidney, and bowel problems. Preventing problems with your bladder and bowels can help prevent AD. Work with caregivers to set up bowel and bladder programs. These programs help prevent bladder distention, bladder infections, constipation, and fecal impaction. Medicines to prevent other frequent problems may also be given. Ask your caregiver if you need these medicines, especially if the cause of your AD takes time to treat.

Where can I find support and more information?

Having autonomic dysreflexia is life changing for you and your family. Accepting that you have AD after a spinal cord injury is hard. You and those close to you may feel helpless, depressed, or frightened. These feelings are normal. Talk to your caregivers, family, or friends about your feelings. You may also want to join a support group. This is a group of people who have spinal cord injuries and who may also have AD. Contact the following for more information:

  • American Spinal Cord Association
    2020 Peachtree Road, NW
    Atlanta, Georgia , 30309-1402
    Phone: 1- 404 - 355-9772
    Web Address:
  • National Spinal Cord Injury Association
    1 Church Street, Suite 600
    Rockville , MD 20850
    Phone: 1- 800 - 962-9629
    Web Address:
  • Paralyzed Veterans of America
    801 Eighteenth Street NW
    Washington, DC , 20006
    Phone: 1- 800 - 424-8200
    Web Address:

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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