What’s The Difference Between Chronic Fatigue, Myalgic Encephalitis, and Systemic Exertion Intolerance Disorder?

Fatigue is the most poorly managed condition in all of medicine. And part of the reason why is that there’s still not a consensus on what makes up pathological levels of fatigue.

Do you chronic fatigue syndrome (CFS)?

Or, maybe it’s myalgic encephalitis (ME)?

Or, was it systemic exertional intolerance disorder (SEID)?

Fatigue has gone through a litany of diagnostic changes. While these changes are aimed to help practitioners better diagnose their patients, the constant name changes bring about loads of confusion.

What is fatigue

Conservative estimates put one in three doctors visits are due to fatigue. (1, 2) And if you’re reading this, I imagine you are one of the three. 
 But what exactly is fatigue?

Is there an agreed upon medical definition of fatigue?

Fatigue, in its most general sense is the difficulty or inability to initiate activity. From your perspective, the medical community has outlined three different areas where you may experience fatigue. These include:

  1. A subjective sense of weakness
  2. A reduced capacity to maintain activity
  3. Difficulty with concentration, memory, and emotional stability.

It is possible to have one of the above or any combination of the above. To further complicate matters, the above fatigue symptoms may occur on their own or combination with any other complaint(s).

Fatigue can also be further classified based on the duration. The three types of fatigue based on duration include:

  1. Acute fatigue
  • Fatigue lasting one month or less
  1. Subacute fatigue
  • Fatigue lasting between one and six months
  1. Chronic fatigue
  • Fatigue lasting over six months.

Were you properly diagnosed?

Before 2015, chronic fatigue syndrome was a disease of exclusion. And even after 2015, chronic fatigue syndrome is still (mostly) a disease of exclusion. That means, chronic fatigue (CFS) will be diagnosed if all your other lab markers for other disease/illness come back within the normal ranges. (5)

Let’s confirm that you have been diagnosed properly. Below, I will ask you a series of questions based on the 2015 and prior method of diagnosis.

  • Do you have severe, persistent fatigue?
  • How long has your fatigue been present?
  • What percentage of the time do you feel fatigued?
  • Does your fatigue noticeably affect your daily physical and work routine?
  • Which issues do you also suffer from?
  • Check each that apply to you
  • Neurocognitive issues
  • memory loss
  • Clumisiness
  • Difficult concentrating or thinking
  • Non-rereshing sleep or sleep issues
  • Muscle or joint pains without swelling or inflammation
  • Headahces
  • Painful or tender lymph nodes
  • Frequent sore throat
  • Mental fogginess
  • Low blood pressure
  • Aggravated allergy symptoms
  • seasonal, food, environmental
  • Irritable bowel syndrome
  • Night sweats
  • Chronic or long-lasting cough
  • Palpitations or escalated heart rate
  • Recurring flu-like illness
  • Undetermined reasons for weight change
  1. If you answered no, you do not have chronic fatigue.
  2. If you answered yes, proceed to the next question.
  3. This must be present for six or more successive months.
  4. If it’s been present for less than six months, you likely have acute or subacute fatigue.
  5. You must feel fatigued for more than 50% of your waking hours
  6. If it’s less, other options need to be explored.
  7. Yes — continue to next question
  8. No — look to other options.
  9. You must have at least 4 concurrent symptoms from the below list

Was your diagnosis legitimate?

Do you have really have chronic fatigue syndrome?

Now remember, this diagnostic criteria is the old way of diagnosing. The new diagnostic criteria is even more robust. So, let’s try a similar questionnaire put through the new criteria.

  1. Do you have a substantial reduction or impairment in your ability to engage in pre-illness levels of occupation, social, or personal activities?
  2. How long has your impairment been occuring?
  3. When did you begin to feel fatigued?
  4. Is your fatigue the result of an ongoing exercise of fitness regime?
  5. Is your fatigue alleviated by rest?
  6. Do you feel more fatigue/symptomatic after exertion?
  7. Do you feel refreshed after sleep?
  8. Do you suffer from one of the two symptoms?
  9. A noticeable decline in cognitive abilities (ie: thinking, memory)
  10. Intolerance to standing upright
  11. What percentage of the time do you feel fatigued?
  12. Yes — continue to next question
  13. No — you do not have chronic fatigue syndrome.
  14. Needs to occur for more than 6 months
  15. This cannot be lifelong. There needs to be a definitive start point.
  16. Yes — this is not chronic fatigue
  17. No — continue to next question
  18. Yes — not chronic fatigue syndrome
  19. No — continue to next question
  20. Yes- chronic fatigue
  21. No — not chronic fatigue
  22. Yes — not chronic fatigue
  23. No — chronic fatigue
  24. Yes — chronic fatigue syndrome
  25. No — not chronic fatigue syndrome
  26. Needs to be greater than 50%

There are three levels of severity in chronic fatigue syndrome. The first level presents with mild symptoms of fatigue. In this state, patients are generally able to take care of themselves. Though they often will skip out on social engagements in order to catch up on sleep. Those classified in the first level of chronic fatigue syndrome are not likely to seek medical attention.

In the second level of severity, there is a moderate presentation of fatigue-related symptoms. These individuals will have limitied ability to perform daily or routine tasks. There is likely to be challenges falling or staying asleep each night. most notable is the individuals ability to only perform a small amount of tasks. Any effort beyond this will result in an exacerbated level of fatigue.

The third level of severity presents with the individual only able to perform basic tasks. Any activity will easily fatigue the individual. This patient may require a wheelchair and will not be able to leave home most of the time.

Where did chronic fatigue come from?

Did you know that the term “chronic fatigue syndrome” was coined in 1988?

At that time, researchers believed long-term fatigue was caused by an Epstein-Barr virus infection. (1) In fact, before 1988, chronic fatigue was even called Epstein -Barr virus syndrome. But the history of chronic fatigue dates back well before 1988.

Going back ro the year 1750, Sir Richard Manningham described a syndrome called febricula. Sir Manningham described febricula as a combination of fever, the common cold, and an inflammation of the veins (phlebitis). While it may not sound much like chronic fatigue syndrome (as it’s known today) this was the medical communities first foray into understanding it.

Fast forward nearly two hundred years and you’ll find research by Dr. George Millar Beard describing an illness he called neurasthenia (nervous exhaustion). Neurasthenia was thought to consist of fatigue, anxiety, headache, impotence, nerve pain, and depression. (2)

Neurasthenia seemed to affect women more often than men. It seemed to occur after an infection. Today, neurasthenia is described as a behaviour, not a medical condition. The world health organization (WHO) no longer lists it as an illness.

Chronic fatigue syndrome (as it’s known today) got its start in 1934 in the County General Hospital of Los Angeles, California. Over two hundred members of hospital staff aquired the disorder.

At this time, symtoms included muscle pain, memoty lapse, difficulty concentrating, sleep disturbance, and inability to walk short distances witout suffering fatigue. At the time, doctors thought the disease was related to polio.

They coined the term poliomyelitis to describe the condition. Three years later, sevety Swiss soldiers were diagnosed with the same condition.

What was going on?

A decade later, in 1948, another outbreak of poliomyelitis occurred. This time in Iceland. It affected more than 1000. Icelanders.

Have you ever heard Chronic Fatigue Syndrome described as Akureyri disease?

Akureyri is the Icelandic town where the outbreak occurred. By the end of the outbreak, epidemiologists differentiated the disease from poliomyolitis.

In 1955, the next outbreak hit the United Kingdom. It occurred in the Royal Free Hospital in 1955. At that time 300 staff members of the hospital fell ill with the disease. Examination of the patients revealed that nearly all of them had their central nervous systems affected.

In 1959, Dr. Ronald Acheson coined the term myalgic encephalomyelitis (ME). (3)

It wasn’t until 1988 that researchers from the CDC (center for disease control) coined the term chronic fatigue syndrome or, CFS. The Holmes criteria were the gold standard used to diagnose chronic fatigue syndrome. (4)

In 2015, the Institute of Medicine (IOM) redefined the diagnostic criteria for chronic fatigue syndrome. At the same time, they re-named the disease. Today, chronic fatigue syndrome is known as Systemic exertion intolerance disease (SEID).

The name change has not yet caught on. So, you may still know the disease as chronic fatigue syndrome.

Along with a name change, the Institute of Medicine aldo revamped the diagnostic criteria. This was changed to exclude more people from the diagnosis. Unfortunately, doctors were diagnosing many people with chronic fatigue syndrome without performing the necessary tests.

Originally published at Fatigue to Flourish.