Could I have done something to prevent orthostatic intolerance/symptoms?

  The short answer - probably not!

It's always easier to look back and say - 'if only I had known what I know now, I could have prevented this.' But that isn't fair to you or any of your caregivers.

Before you can seriously answer this question, there are 2 things to consider.

The first thing to consider is whether you or your doctors could have known that an acute event would not get better quickly and not cause future problems. In most cases, the answer would be no. This is especially true when the acute event that triggered all this was an infection, like the GI flu, herpes infection, shingles, or another infection. In most cases, a person gets sick and recovers - end of story. Taking steps to preventing orthostatic intolerance is usually not part of the management. If the trigger event was surgery or a head injury, the answer would be a little more complicated. It would depend on how long the recovery took, whether there was an ICU stay and how long a person was on bedrest. For more about prolonged bedrest and ICU stays, check out Bedrest , or Space flight, bed rest and OI and ICU-stays

The second practical question has 2 parts.

      » The first part is whether it is known what kind of activities need to be done when a person is sick and on bedrest to prevent OI from developing.

      » The second part is whether it is even possible for a person who is sick to do what it takes.

In most cases - the answer is still no. You probably could not have prevented this from happening. The next questions are whether you can prevent it from getting worse and can you recover from it.

  • How all this started
  • What it takes to prevent OI
  • Can I prevent it from getting worse?
What started all this? Example Did it involve bedrest to get better? Is preventing OI part of the management?
Acute event
(a sudden illness or injury - accident, concussion)
Infection, head trauma, surgery, pregnancy

Preventing OI was not an issue at the time of your illness or injury. It has not been part of the usual care for hospital illness or for prolonged illness at home.

On top of the changes to your system from this event, there were probably more changes as your body adapted to the bedrest. This is called 'secondary deconditioning' - the deconditioning comes after the first event (the infection, head trauma)

Another medical condition with autonomic dysfunction
Diabetes, Parkinson's Disease, Sjögren's syndrome

The OI is caused by the autonomic dysfunction, the damage to the autonomic nervous system.

These conditions do not usually have long periods of bedrest. They would be less likely to have 'secondary deconditioning'

An infection, virus
Any viral infection: GI, respiratory

It is thought there is partial autonomic nervous system damage from the immunologic response. It is expected to heal with time. You could not have altered the immunologic damage to the ANS.

On top of the changes to your system from this event, there were probably more changes as your body adapted to the bedrest. ('Secondary deconditioning')

Taking precautions to prevent OI during your recovery from the infection has not been part of the usual management of these types of illnesses.

Becoming an adolescent, starting your menstrual cycle

Not much you can do about this!!! If this is the only possible cause, most will outgrow it. Until then, there are things you can do to decrease how much it affects your life.

The answer to this question depends on the situation you are looking at: space flight, ICU-stays, or after infections or other acute events.

Space Flight Experience: There is more research on preventing orthostatic intolerance from space flight. It has used healthy people, mostly men, and simulated bedrest situations. But they have identified 2 things that the research suggests contribute to orthostatic intolerance (OI):
   •   Lower blood/plasma volume and
   •  Deconditioning of the cardiovascular system, starting with a decrease in heart muscle size and strength.3

Research Results: preventing OI from developing after bedrest4

Restoring Plasma/Blood Volume: They documented that the plasma volume decreased after 18 days of bedrest. It took 300-435 cc given by vein (IV) to replace it. However, just replacing the volume did not prevent the person from developing orthostatic intolerance.

Exercising Required: The subjects had to exercise 30 minutes, 3 times a day, on a supine bicycle, at 75% of maximum heart rate. However, exercising even this much was not enough by itself to prevent the person from developing orthostatic intolerance.

What this means to you If you are focusing on what the research shows that would help in your everyday life with OI -POTS, there are 3 important things about this research.

  • They showed that both fluids/volume and exercise are needed to prevent orthostatic problems from prolonged bedrest.(To keep from becoming "orthostatic intolerant" , which means not being able to stand up without getting symptoms.)
  • They showed it is possible to prevent orthostatic intolerance (OI) in a research setting.
  • BUT - the amount of exercise the subjects had to do is way more than a person could do when they are sick, e.g. in the ICU or in bed with an infection. (30 minutes, 3 times a day, 75% max heart rate)
  • They did show that exercise could work - and not make things work. BUT they had people do supine bicycling (sitting bicycle). Most other studies and recovery programs have the subjects standing up, using a treadmill or bicycle. They do not show positive results. See Recovery from OI and Move into Health for more information.
  • Their research and results is being used in a recovery program for people with POTS. For more information about this, go to OI Recovery Programs.

Preventing OI during ICU-stays - Research with ICU patients hasn't come up with the answer although they are trying different approaches: passive exercising, resistance exercising, early walking.5,6  There's more information here - Bedrest - Space Flight and ICU-Stays.

Preventing OI during s - Research is needed to understand what would work in real-life situations with people who are ill and cared for at home. .


We hope so. With the information provided here, what you've learned about yourself and what works for you, and your physician and healing team, we hope you will learn how to prevent it from getting worse.

We hope you can go even further to have a life you enjoy and not be limited by or defined by orthostatic symptoms, POTS, or NMH.

  1. Low PA, Sandroni P, Joyner and Shen W. Postural Tachycardia Syndrome (POTS). J Cardiovasc Electrophysiology 2009; 20:352-358.  Abstract.  Article PDF
  2. Lee et al. Aerobic Exercise Deconditioning and Countermeasures During Bed Rest. Aviation, Space, and Environmental Medicine January 2010;81(1): 52-63.  Abstract.  Article PDF.
  3. Fu Q, Vangundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, Bhella PS, Levine BD. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010 Jun 22;55(25):2858-68. Abstract. Article PDF
  4. Shibata S, Perhonen M, Levine BD. Supine cycling plus volume loading prevent cardiovascular deconditioning during bedrest . J Appl Physiol. 2010 May;108(5):1177-86. Epub 2010 Mar 11.  Abstract.  Article PDF
  5. Denehy L, Berney S, Skinner E, Edbrooke L, Warrillow S, Harthorne Graeme and Morris ME.   Evaluation of exercise rehabilitation for survivors of intensive care: Protocol for a single blind randomized controlled trial.The Open Critical Care Medicine Journal 2008; 1: 39-47.
  6. Berney S, Haines KJ, and Denehy L.   Physiotherapy in Critical Care in Australia. Cardiopulmonary Physical Therapy Journal. 2012; 23(1):19-25.

Author: Kay E. Jewell, MD
Page Last Updated: August 12, 2012