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Part 1- Accurate Diagnosis: Fibromyalgia vs. Chronic Fatigue Syndrome vs. Myalgic Encephalomyelitis

Unfortunately, there's a negative stigma associated with having Fibromyalgia (FM) or Chronic Fatigue Syndrome (CFS) - also known as Myalgic Encephalomyelitis (ME). People with either diagnosis are often perceived as being ‘lazy’ hypochondriacs and some have been told that "it's all in your head." I've heard stories of patients being denied referrals for care because their doctor doesn’t believe in it. Many health practitioners and the general public are skeptical of the legitimacy of the diagnosis.

The reality: people with FM or CFS/ME are struggling with profound, debilitating pain and fatigue (amongst other symptoms). An accurate and prompt diagnosis (specifically for CFS/ME) is important because it’s been found that late diagnosis and over-exertion in the early stages of the illness have been associated with increased symptom severity and poor prognosis.

This blog post will review the current diagnostic criteria for both conditions. My intent is to: 1. challenge those with the belief that these conditions aren't real 2. Educate healthcare providers, so that they can better recognize this condition.

Fast Facts:

CFS/ME are synonymous terms that describe the same condition.

CFS/ME and FM are co-morbid conditions, meaning that even though they are diagnostically different, it's common for a person to have both at the same time. They're considered to be 'overlap syndromes.'

Other co-morbid conditions include: myofascial pain syndrome, temporomandibular joint syndrome, irritable bowel syndrome, interstitial cystitis, irritable bladder syndrome, Raynaud’s phenomenon, prolapsed mitral valve, migraine, allergies, multiple chemical sensitivities, thyroiditis, sicca syndrome, depression, Hashimoto’s, etc.

Mainly women are affected.

There’s no single blood test or investigation for the diagnosis of CFS/ME or FM.

There is generally some sort of precipitating event prior to onset of symptoms. Examples include: physical trauma like a car accident, an infection (usually viral), or major emotional trauma like a death in the family.


Why the difficulty with diagnosis, acceptance, and management?

1. There are at least 20 clinical and research definitions specifically for CFS/ME. That means the inclusion criteria for selecting patients to study has been inconsistent which makes it tricky to draw conclusions from research. For FM, a new criteria exists (2010) that has replaced the former requirement of 11/18 tender points.

2. Insufficient training in medical schools. Many doctors haven't received adequate education on the diagnosis and management of these conditions. This is tightly related to the point above - what do you teach when there are various definitions that keep changing and there's limited understanding of the pathophysiology of the condition?

3. Practitioner time and interest. Both are required for a healthcare practitioner to keep up with all the changes in diagnostic criteria. MDs barely have time to eat their lunch in a workday, so unfortunately they’re in short supply of time to keep up to date on this condition.

4. Sparse funding for research.


Diagnostic Criteria for CFS/ME using The Canadian Consensus Criteria:

1. Symptoms can't be better explained by another medical condition (large list that must be first ruled out) If you are a healthcare provider, see reference #1 below. This doesn't include co-morbid conditions.

2. Symptoms are Chronic - usually with a gradual onset.

> 3 months for children

>6 months for adults

3. Fatigue - that is persistent and can’t be explained by another medical condition. It has both physical and mental components.

4. Pain - that affects muscles and joints. It’s often migratory and meets the diagnostic criteria for FM - hence, they're co-morbid conditions.

5. Post-exertional malaise and fatigue - this is the characteristic “crash” or worsening of symptoms that happens after minimal physical or mental exertion. There is a delay in recovery that is disproportional to the exertion required by the activity.

6. Sleep Dysfunction - where the patient rarely wakes feeling refreshed. There could be issues with falling asleep, staying asleep, and/or sleep stages are aberrant. Sleep studies are generally warranted.

7. Cognitive Dysfunction - requires two or more of the following: confusion, impaired concentration, poor attention, slowed processing of information, poor short-term memory, disorientation to place, difficulty with categorizing and impaired word retrieval.

8. At least one symptom from two of the following:

Automatic Nervous System Dysfunction - sweating abnormalities, dizziness/fainting, inability to alter heart rate with exercise, digestive issues, urinary problems, sexual problems, and visual problems

Neuroendocrine Dysfunction - changes in appetite, body weight, less tolerance for stress, cold extremities, etc.

Immune Dysfunction - flu-like aches; chronic enlarged lymph nodes; hyper responsive immune system leading to sensitivities to: food, medications, and/or chemicals; skin rashes; frequent infections and allergies.


Diagnostic Criteria for FM based on The American College of Rheumatology (2010)

This is based on two validated questionnaires: Widespread Pain Index (WPI) and Symptom Severity Scale (SS).

WPI≥ 7 and SS ≥ 5


WPI≥ 3-6 and SS ≥ 9


Patients that meet the criteria for CFS/ME and/or FM vary in their degree of symptom severity and functional impairment. Some are able to hold a job whereas others are completely bedridden and everyday tasks that we take for granted (like brushing teeth) become extremely difficult. Many experience social isolation and depression. Imagine feeling terrible, not understanding what's going on in your body, and people not taking you seriously?

These are complex, chronic conditions so it’s difficult to cover everything in a blog post which is why I’m dividing this topic into different parts. I'll get technical in Part 2 and explore the pathophysiology to explain how the disrupted cellular processes cause the various symptoms associated with CFS/ME and FM. Part 3 will explore prognosis and treatment options.

Special thanks to Dr. Louise McCrindle ND who advocated for a focus shift at CCNM (many years ago) that is completely dedicated to training fourth year naturopathic medical interns in the treatment and management of CFS/ME and FM. She was one of my supervisors during my clinical residency and I wouldn't have the knowledge or clinical training without her!

This blog is to serve as information purposes only. It's not meant to diagnose, treat, cure, or prevent any conditions. Please seek the advice of a healthcare provider to address your individual concerns.


Bested AC, Marshall LM. Review of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: an evidence-based approach to diagnosis and management by clinicians. Reviews on environmental health. 2015 Dec 1;30(4):223-49.

Pheby D, Saffron L. Risk factors for severe ME/CFS. Biol Med 2009;1(4):50–74

Wolfe F, Clauw DJ, Fitzcharles MA, Goldenberg DL, Katz RS, Mease P, Russell AS, Russell IJ, Winfield JB, Yunus MB. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis care & research. 2010 May 1;62(5):600-10.

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