How a diagnosis of ME/CFS is made

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can affect anyone of any age and any background. 

While there is currently no diagnostic test for ME/CFS, an accurate diagnosis is straightforward when using accepted diagnostic criteria. Diagnosis should also involve the exclusion of other possible diagnoses that could be the cause of the symptoms. Healthcare practitioners can access an RACGP accredited online professional module with more information on how to accurately diagnose ME/CFS here

It is also common for people with ME/CFS to have other conditions in addition to ME/CFS, such as fibromyalgia, irritable bowel syndrome (IBS), or postural orthostatic tachycardia syndrome (POTS). 

Diagnostic criteria for ME/CFS

There have been many different diagnostic criteria developed for ME/CFS over several decades. However, most of these do not require post-exertional malaise (PEM) as a symptom, even though it is considered a core feature of the condition, and so are no longer recommended.

Following the recommendations of the National Health and Medical Research Council’s ME/CFS Advisory Committee and the US Centers for Disease Control and Prevention (CDC), Emerge Australia advocates use of the US National Academy of Medicine (NAM) criteria for clinical use, and the Canadian Consensus Criteria (CCC) for research purposes, both of which require PEM for diagnosis.

US National Academy of Medicine (NAM) criteria

In its 2015 report, NAM noted that an estimated 90% of people living with ME/CFS are undiagnosed. The NAM criteria were designed to simplify the diagnostic process, in order to make it easier for doctors to diagnose ME/CFS when it is present in their patients. Early diagnosis helps ensure that people living with ME/CFS get advice to live within their energy envelope, and minimise the risk of their condition worsening. 

The minimum symptoms required for diagnosis using the NAM criteria are:

  • substantial reduction in the ability to engage in pre-illness activity. This must have persisted for six months or more, and be accompanied by profound fatigue that isn’t substantially improved with rest
  • post-exertional malaise (PEM), which is the worsening of symptoms following physical or mental exertion
  • unrefreshing sleep

Plus, either:

  • problems with memory, thinking or concentration
  • difficulty being upright (dizziness, sweating, nausea or other symptoms when standing that are reduced when lying down)

These are not the only symptoms that people with ME/CFS experience, nor are they the only common symptoms. They are the minimum symptoms required to meet the diagnosis of ME/CFS using the NAM criteria. 

Canadian Consensus Criteria (CCC)

In research, strict diagnostic criteria are important to ensure that samples being studied are homogenous. The CCC are widely used in ME/CFS research. These criteria are more complicated than the NAM criteria, and not as easy to use clinically, though they are still valid in a clinical setting. The CCC can be downloaded from here. Please note that this is an original article and will incur cost to download. Academics may be able to get access through their home institutions and we are working to produce a downloadable document with key points. Please contact us if you would like a working version of this document. 

Severity of ME/CFS

  • mild: 50% reduction in pre-illness activity
  • moderate: mostly housebound
  • severe: mostly bedridden
  • very severe: totally bedridden and need help with basic functions

ME/CFS is not a psychiatric diagnosis

ME/CFS is not a psychiatric condition, like depression or anxiety. Understandably, some people may develop depression or anxiety as a result of being diagnosed with, or living with, a chronic illness. However, ME/CFS is not a psychosocial or psychosomatic condition.