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 have chronic fatigue syndrome (CFS)?
Or, maybe it’s myalgic encephalomyelitis (ME)?
Or, was it systemic exertional intolerance disorder (SEID) that you were diagnosed with?
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?
Is there an agreed upon medical definition of fatigue?
Turns out, there is a medical definition of fatigue. Fatigue, in its most general sense, is the difficulty or inability to initiate activity. The medical community has outlined three different areas where you may experience fatigue. These include:
- A subjective sense of weakness.
- A reduced capacity to maintain activity.
- A difficulty with concentration, memory, and/or 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 combined with any other complaint(s).
Fatigue can also be further classified based on the duration. The three types of fatigue based on duration include:
- Acute fatigue
- Fatigue lasting one month or less
- Subacute fatigue
- Fatigue lasting between one and six months
- Chronic fatigue
- Fatigue lasting over six months.
Ok, so now you (hopefully) know what constitutes pathological fatigue.
But where did chronic fatigue come from? And how is it different than myalgic encephalomyelitis (ME) or systemic exertional intolerance disease (SEID)? What exactly is the criteria needed to diagnose chronic fatigue syndrome?
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. 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 to the year 1750, Sir Richard Manningham described a syndrome called febricula. Sir Manningham described febricula as a combination of fever, the common cold, and inflammation of the veins (phlebitis). While it may not sound much like chronic fatigue syndrome (as it’s known today) this was the medical community’s 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. (3) Neurasthenia seemed to affect women more often than men. It also seemed to occur after an infection. Today, neurasthenia is described as a behavior, 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 acquired the disorder. At this time, symptoms included muscle pain, memory lapse, difficulty concentrating, sleep disturbance, and inability to walk short distances without suffering fatigue. Doctors thought the disease was related to polio. They coined the term poliomyelitis to describe the condition. Three years later, seventy 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 poliomyelitis.
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). (4) 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 at that time. (5)
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 (CFS) or even myalgic encephalomyelitis (ME). Along with a name change, the Institute of Medicine also 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 necessary tests.
Was your fatigue 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 diseases/illnesses come back within the normal ranges. (6)
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. This is the old diagnostic criteria for chronic fatigue syndrome. Please note this criterion is different than the one used for systemic exertional intolerance disease (SEID).
Take out a pen and paper to answer the questions the in numerical order. After you’ve finished answering the questions, go through the diagnostic criteria I describe. This is located just below the questions.
Chronic fatigue syndrome diagnostic criteria (questions)
1. How long has your fatigue been present?
2. What percentage of the time do you feel fatigued?
3. Does your fatigue noticeably affect your daily physical and work routine?
4. Which issues do you also suffer from? Check each that applies to you:
- Neurocognitive issues
- Memory loss
- Difficulty concentrating or thinking
- Non-refreshing sleep or sleep issues
- Muscle or joint pains without swelling or inflammation
- 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
Chronic fatigue syndrome diagnostic criteria (answers)
1. This must be present for six or more successive months.
- If it’s been present for less than six months, you likely have acute or subacute fatigue.
2. You must feel fatigued for more than 50% of your waking hours.
- If it’s less, other diagnoses need to be explored.
3. Yes – continue to next question
- No – look to further tests to explain symptoms.
4. You must have at least 4 concurrent symptoms from the above list
Was your diagnosis legitimate? Do you have really have chronic fatigue syndrome?
Now, remember, this diagnostic criterion is the old way of diagnosing chronic fatigue. The new diagnostic criteria are even more robust. So, let’s try a similar questionnaire done with the new diagnostic criteria. These questions are used to diagnose systemic exertional intolerance disease (SEID) not chronic fatigue syndrome (CFS).
Just like you did in the previous sections, take out a pen and paper to answer the questions the in numerical order. After you’ve finished answering the questions, go through the diagnostic criteria I describe. This is located just below the questions.
Systemic exertional intolerance disease diagnostic criteria (questions)
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 occurring?
3. When did you begin to feel fatigued?
4. Is your fatigue the result of an ongoing exercise or 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?
- A noticeable decline in cognitive abilities (ie: thinking, memory)
- Intolerance to standing upright
9. What percentage of the time do you feel fatigued?
Systemic exertional intolerance disease diagnostic criteria (answers)
Below is the rubric to see if you qualify for the diagnosis of systemic exertion intolerance disorder (SEID). Notice how the criteria are now different than they were for chronic fatigue syndrome.
1. If you answered yes, this impairment needs to have occurred for more than 6 months.
- If you answered no, you do not have systemic exertion intolerance disorder (SEID).
2. Needs to occur for more than 6 months.
3. This cannot be lifelong. There needs to be a definitive start point.
4. If you answered yes, this is not systemic exertion intolerance disorder (SEID)
- If you answered no, continue to the next question.
5. If you answered yes, your condition is not systemic exertion intolerance disorder.
- If you answered no, continue to next question.
6. If you answered no, your condition is not systemic exertion intolerance disorder.
- If you answered yes, continue to next question.
7. If you answered yes, your condition is not systemic exertion intolerance disorder.
- If you answered no, continue to next question.
8. If you answered yes, you are positive for systemic exertion intolerance disorder.
- If you answered no, you do not have systemic exertion intolerance disorder
9. You need to experience fatigue more than 50% of the time.
The major differences between chronic fatigue syndrome (CFS) and systemic exertional intolerance disease (SEID) are as follows:
- There needs to be a specific point in time where your fatigue began. It cannot have happened your whole life.
- Your fatigue cannot be associated with any exercise or fitness program.
- Your fatigue cannot be alleviated with rest.
- Unrefreshing sleep now needs to be associated with the fatigue.
- You need to experience either a decline in your cognitive abilities or intolerance to standing upright.
These new additions to the diagnostic criteria of chronic fatigue are beneficial. They force doctors to run more tests on their patients to rule out other potential causes of fatigue. I believe this to be a very important development in the treatment and management of the illness.
Your next steps towards a proper diagnosis
If your fatigue diagnosis came before 2015, I encourage you to book a follow-up appointment with your physician. Go through the new diagnostic procedures together. Make note of whether (or not) you still fit the diagnostic criteria.
If you no longer fit the diagnostic picture, be assertive. Ask your doctor to perform more testing. Testing that can help you identify the root cause of your fatigue. If your lab tests still come back within normal ranges, it’s time to find a knowledgeable functional medicine practitioner.
Now, I want to hear from you!’
Did the change in diagnostic criteria affect your diagnosis?
Do you really have chronic fatigue syndrome?
Want to know more than your doctor about fatigue? Click here to learn the best ways to achieve a clear, focused mind.
Also published on Medium.