Autonomic Dysreflexia / hyperreflexia : Signs & Symptoms, Causes, Treatment

November 2, 2012 | By | Reply More

Autonomic Dysreflexia / hyperreflexia : Signs & Symptoms, Causes, Treatment

Autonomic dysreflexia, also known as hyperreflexia, means an over-activity of the Autonomic Nervous System causing an abrupt onset of excessively high blood pressure. Persons at risk for this problem generally have injury levels above T-5. Autonomic dysreflexia can develop suddenly and is potentially life threatening and is considered a medical emergency. If not treated promptly and correctly, it may lead to seizures, stroke, and even death.
AD occurs when an irritating stimulus is introduced to the body below the level of spinal cord injury, such as an overfull bladder. The stimulus sends nerve impulses to the spinal cord, where they travel upward until they are blocked by the lesion at the level of injury. Since the impulses cannot reach the brain, a reflex is activated that increases activity of the sympathetic portion of autonomic nervous system. This results in spasms and a narrowing of the blood vessels, which causes a rise in the blood pressure.

Signs & Symptoms

  • Pounding headache (caused by the elevation in blood pressure)
  • Goose bumps
  • Sweating above the level of injury
  • Nasal Congestion
  • Blotching of the Skin
  • Restlessness
  • Hypertension (blood pressure greater than 200/100)
  • Flushed (reddened) face
  • Red blotches on the skin above level of spinal injury
  • Sweating above level of spinal injury
  • Nausea
  • Slow pulse (< 60 beats per minute)
  • Cold, clammy skin below level of spinal injury


  • There can be many stimuli that cause autonomic dysreflexia. Anything that would have been painful, uncomfortable, or physically irritating before the injury may cause autonomic dysreflexia after the injury.
  • The most common cause seems to be overfilling of the bladder. This could be due to a blockage in the urinary drainage device, bladder infection (cystitis), inadequate bladder emptying, bladder spasms, or possibly stones in the bladder.
  • The second most common cause is a bowel that is full of stool or gas. Any stimulus to the rectum, such as digital stimulation, can trigger a reaction, leading to autonomic dysreflexia.
  • Other causes include skin irritations, wounds, pressure sores, burns, broken bones, pregnany, appendicitis, and other medical complications.
  • In general, noxious stimuli (irritants, things which would ordinarily cause pain) to areas of body below the level of spinal injury. Things to consider include:

Bladder (most common) – from overstretch or irritation of bladder wall
Urinary tract infection
Urinary retention
Blocked catheter
Overfilled collection bag
Non-compliance with intermittent catheterization program
Bowel – over distention or irritation
Constipation / impaction
Distention during bowel program (digital stimulation)
Hemorrhoids or anal fissures
Infection or irritation (eg. appendicitis)

  • Skin-related Disorders

Any direct irritant below the level of injury (eg. – prolonged pressure by object in shoe or chair, cut,
bruise, abrasion)
Pressure sores (decubitus ulcer)
Ingrown toenails
Burns (eg. – sunburn, burns from using hot water)
Tight or restrictive clothing or pressure to skin from sitting on wrinkled clothing

  • Other

Heterotopic ossification (“Myositis ossificans”, “Heterotopic bone”)

Acute abdominal conditions (gastric ulcer, colitis, peritonitis)

Skeletal fractures


Treatment must be initiated quickly to prevent complications.
Remain in a sitting position, but do a pressure release immediately. You may transfer yourself to bed, but always keep your head elevated.
Since a full bladder is the most common cause, check the urinary drainage system. After correcting an obvious problem, and if your catheter is not draining within 2-3 minutes, your catheter must be changed immediately. If you do not have a Foley or suprapubic catheter, perform a
catheterization and empty your bladder.

If your bladder has not triggered the episode of autonomic dysreflexia, the cause may be your Bowel. Perform a digital stimulation and empty your bowel. If you are performing a digital stimulation when the symptoms first appear, stop the procedure and resume after the symptoms subside.

If your bladder or bowel are not the cause, check to see if: You have a pressure sore or You have an ingrown toenail or You have a fractured bone.
Identify and remove the offending stimulus whenever possible. Often, this alone is successful in allowing the syndrome to subside without need for pharmacological intervention.

If symptoms persist despite interventions such as the foregoing, notify a physician.


Medications are generally used only if the offending trigger/stimulus cannot be identified and removed or when an episode persists even after removal of the suspected cause.

Category: Medical, Medicine

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