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What is autonomic dysreflexia?

Autonomic dysreflexia is a condition that is most common in people with spinal cord injuries above T6. Some people with multiple sclerosis can also experience this condition. It happens when stimuli below the level of the injury causes the blood vessels to constrict. This then causes the person's blood pressure to rise very quickly. If you take away the stimulus, the autonomic dysreflexia usually stops.

If you are supporting someone with these conditions, you need to know the signs and symptoms of autonomic dysreflexia and what to do. It's also important that you follow the person's toileting management plan. You need to know what is normal for the person you support. This will help you to notice if something changes.

Autonomic dysreflexia is a medical emergency. It can be life threatening and lead to:

  • stroke
  • retinal haemorrhage
  • cardiac arrest.

What are the signs and symptoms of autonomic dysreflexia?

Raised blood pressure. Important note: an adult with a spinal cord injury above T6 usually has a low blood pressure, such as 9O/6O or 1OO/7O. So, someone like this can experience autonomic dysreflexia when their blood pressure reaches what is considered normal in most people (12O/8O).

As well as raised blood pressure, the person may experience one or more of these symptoms:

  • a very bad headache
  • flushed blotchy skin above the level of their injury
  • sweating above the level of their injury
  • blurred vision
  • blocked nose
  • feeling anxious or worried.

If the person you support has the above signs and symptoms, get medical help straight away.

They don't need to have all of the symptoms above to experience autonomic dysreflexia.

What causes autonomic dysreflexia?

Autonomic dysreflexia can happen if the person:

  • isn't able to pass urine, causing their bladder to be overfull (this is the most common cause)
  • has a blocked urinary catheter, that stops urine draining from the bladder
  • has a kinked catheter
  • has a urinary tract infection
  • has constipation or has a bowel impaction
  • has haemorrhoids.

Autonomic dysreflexia can also happen during a person's routine bowel management. Rectal or digital stimulation during bowel care or if the bowel motion is difficult to pass, can cause autonomic dysreflexia. This may be short-term and stop with no harmful effects when the stimuli has been taken away, e.g. the bowel motion has been passed. If the symptoms don't get better as soon as the stimuli has been taken away, get medical help straight away.

What should you do if the person you support has autonomic dysreflexia?

  • Help the person into a sitting position and lower their legs.
  • Loosen any tight clothing.
  • Look for the stimuli causing the autonomic dysreflexia and take it away if you can e.g. if the catheter is kinked, unkink it.

If you can't find and remove the cause, call for medical help. You shouldn't ignore autonomic dysreflexia.

How can you stop it from happening?

Long-term treatment and management should look at what causes autonomic dysreflexia for that person. This could be different for each person. Always follow a toileting management plan developed by a health care professional. If there isn't a toileting plan in place, talk to your supervisor, the person's care co-ordinator or other health care professional.

Need more help? Call the National Continence Helpline on 18OO 33 OO 66 and talk to a continence nurse advisor.

Take the Quiz

Question 1

To experience autonomic dysreflexia there must be damage, injury or disease to:

the brain

the heart

the spinal cord at or above T6

none of the above.

Question 2

The first thing to do if someone is experiencing autonomic dysreflexia is:

call an ambulance

call your supervisor

lay the person down and look for a cause

sit the person up and look for a cause.

Question 3

When experiencing autonomic dysreflexia the person will have:

raised blood pressure


shortness of breath

clear vision.

Question 4

Symptoms of autonomic dysreflexia are:

blurred vision

pounding headache

sweating above the level of their injury

all of the above.

This information is not a substitute for independent professional advice.