In addition to ME/CFS, it is common for people living with ME/CFS to have other conditions, including:

  • fibromyalgia
  • orthostatic intolerance (OI)

What is fibromyalgia?

Fibromyalgia is a condition that causes widespread pain and muscle stiffness throughout the body. 

How are fibromyalgia and ME/CFS connected? 

There is agreement within the medical community that fibromyalgia and ME/CFS are similar conditions, and may be related. However, the major difference between the two conditions is the predominant symptom. Although the two conditions share widespread pain, fatigue and a variety of similar symptoms, their primary features are different. While the primary feature of fibromyalgia is widespread pain, the primary feature of ME/CFS is post-exertional malaise (PEM). 

Emerge Australia represents people with ME/CFS who may have a secondary diagnosis of fibromyalgia. If you have received a primary diagnosis of fibromyalgia, Arthritis Australia has a wealth of resources, knowledge and support for your diagnosis. 

What are the symptoms of fibromyalgia?

Symptoms of fibromyalgia include: 

  • pain across the body, usually described as aching, stiffness and tenderness 
  • extreme fatigue 
  • difficulties with sleeping 
  • problems with concentration and memory 
  • headaches 
What are the treatments of fibromyalgia?

There is no cure for fibromyalgia. However, with the right approach and management plan, people with fibromyalgia can ease some of the pain and discomfort and enjoy improvements in their quality of life. 


What is orthostatic intolerance?               

Orthostatic intolerance (OI) is an “umbrella term” for a number of conditions where symptoms are made worse by sitting or standing.

Some definitions that will help you understand OI

  • orthostatic = an upright posture, either sitting or standing
  • tachycardia = fast heart rate
  • hypotension = low blood pressure
  • autonomic nervous system = Your autonomic nervous system controls all of your body functions you don’t need to think about, such as heart rate, blood pressure, breathing and digesting.

There are a number of different forms of orthostatic intolerance, these are:

  • Postural Orthostatic Tachycardia Syndrome (POTS)
  • Orthostatic hypotension (OH)
  • Neurally mediated hypotension (NHH)
What are the symptoms of orthostatic intolerance? 

When you stand up, gravity causes an increase in blood to the lower part of your body. In in a healthy person, your autonomic nervous system regulates blood flow very quickly, and you experience no symptoms. In someone with OI, the autonomic nervous system has problems adjusting. This means that there is a decrease in blood flow to other areas of the body.

What are the symptoms of orthostatic intolerance?

  • lightheaded or dizzy when sitting or standing
  • intolerance to heat and/or cold
  • trouble concentrating
  • word finding problems
  • nausea
  • feeling shaky
  • fatigue
  • headache
  • heart palpitations

Often, these symptoms become less or go away completely when you sit or lie down again.

How are orthostatic intolerance and ME/CFS connected?

Orthostatic intolerance is common in people with ME/CFS and can contribute significantly to the level of disability experienced. There is growing awareness that orthostatic stress may also contribute to post-exertional malaise (PEM).

There are many causes of orthostatic intolerance. It is important you work with your doctor to find out if ME/CFS is the cause for you.

Emerge Australia supports people living with ME/CFS who may have a co-diagnosis of orthostatic intolerance. If you have received a primary diagnosis of orthostatic intolerance in any of its forms, Dysautonomia International has a wealth of resources, knowledge and support for your diagnosis.

Are there objective measurements to show you have orthostatic intolerance?

There are some tests your doctor can do in their office to determine if you have orthostatic intolerance. These include:

  • Testing to see if your heart rate and/or blood pressure change from lying to standing. This is called a NASA lean test
  • A tilt-table test in a cardiology or neurology department

NOTE: Sometimes tests come back “normal”. However, if you experience problems with sitting and standing, you may still have orthostatic intolerance. Research suggests people with ME/CFS have a 25% decrease in blood flow to the brain on sitting or standing, even when their blood pressure and heart rate measurements are normal1.

What are the treatments for orthostatic intolerance?

There are many different causes of orthostatic intolerance. Treatment and management will depend on the underlying cause. When it is not possible to find the underlying cause, treatment focusses on managing symptoms.

Treatments can be divided into two types, lifestyle management and medication. All treatments should be in consultation with your treating doctor, who knows your medical history and can determine if they are safe for you.

Lifestyle management strategies

  • a high salt diet
  • adequate fluids
  • compression garments – these should be fitted correctly
  • exercise – Exercise is not usually considered safe for people with ME/CFS. Preventing post-exertional malaise should come before any attempt at exercise.
  • mobility aids such as walking sticks or wheelchairs
  • use a shower seat as hot water can make the symptoms feel worse

Medication management strategies 

There is no “one size fits all” approach to medication. You will need to discuss with your doctor the potential risks and benefits, including other medical conditions such as allergies.

With the right approach and management plan, you can ease some of the disability associated with orthostatic intolerance, which will improve your quality of life.

1. Bateman, L. et al. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Essentials of Diagnosis and Management. Mayo Clinic Proceedings 96, 2861–2878 (2021).