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The Difference Between Chronic Fatigue and Chronic Fatigue Syndrome

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May 12th is International ME/CFS and FM Awareness Day, and throughout the month people are sharing posts which shed a bit more light on these misunderstood illnesses. For more, check out #May12BlogBomb, #MEAwarenessDay and #MillionsMissing on Twitter and Instagram. 

One of the most common misconceptions about myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the difference between the specific illness and other types of fatigue. This simple misunderstanding snowballs into real challenges for those with ME/CFS, who have to contend with people’s assumptions that they are not seriously unwell – just tired.

The common name of the disease (chronic fatigue syndrome) encourages these misconceptions. The conflation between different types of fatigue is just one of the many reasons why I believe chronic fatigue syndrome should be completely replaced with the term “myalgic encephalomyelitis.”

An image of a young woman at a desk The desk is piled with papers and mugs The woman has brown hair and wears a brown jacket She rests her head on the papers and her eyes are closed

Above: The fact that images like this inevitably accompany articles about ME/CFS doesn’t help.

Today I will compare different types of fatigue to make clear the difference between other types of tiredness and ME/CFS.


We all get tired. Even perfectly healthy individuals experience ordinary fatigue in the course of their day. Some examples of fatigue as a normal response to life circumstances include:

  • Not sleeping well due to the heat and feeling drowsy the next day
  • Being tired after a long day of work
  • Feeling fatigued due to stressful life circumstances
  • Being worn out after a gym session
  • Having a newborn baby and being exhausted from their constant screaming and crying

A screenshot from Spongebob Squarepants Patrick Star a starfish wears business clothing and sits in lounge chair at front He looks back with disinterest To the left and behind is Spongebob Squarepants an ocean sponge with multiple arms each performing a cleaning task He has a look of dismay

Before I fell ill, I had trouble sleeping and used to complain of exhaustion after not catching a break for days at a time (god, I wish I could go back to those days!). School was taxing, and I would get a bit worn out after traveling hours in a day just to get close to civilization. But that did not mean I had a chronic illness.

One of the quickest ways to get on the wrong side of someone with a chronic illness is to try to compare your healthy tiredness to their debilitating, medically-induced fatigue. Trust me when I say you don’t understand what someone with a chronic illness is going through just because you are a bit worn out after achieving things they might not come close to in their wildest dreams.

Does your fatigue have a (reasonable) cause? Then you’re probably not sick, just human.

Chronic Fatigue

Chronic fatigue is a hallmark of a great number of chronic illnesses. I would even go so far as to say that nearly every chronic illness has the symptom of chronic fatigue – but that does not mean those who experience it have chronic fatigue syndrome.

Generally, if chronic fatigue has another medical explanation (such as another illness), you are precluded from being diagnosed with chronic fatigue syndrome. It’s not a tack-on at the end of a list of multiple illnesses; it is an illness in its own right with a very specific set of symptoms. Here are some examples of how people with chronic illnesses can experience chronic fatigue:

  • A Crohn’s patient who is worn out by pain and inflammation
  • Someone with POTS who is so weak and dizzy they are unable to shower themselves
  • Someone who has depression and finds their fatigue so overwhelming they cannot leave their bed

An image of a Gumby-style red toy It has a sad expression on its face and holds its hands up to its head

Above: While we’re talking about pictures that inadequately represent illnesses, what’s worse: the ME/CFS tired lady, or this faux-Gumby picture I found under stock images of depression?

In fact, chronic fatigue is such a universal symptom, it makes me wonder why one specific disease with a myriad of symptoms was singled out to be named “chronic fatigue syndrome” when you could practically name any disease the same.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

We’ve finally made it to chronic fatigue syndrome: the disease. As I’ve explained, “fatigue” does not quite cover the range of symptoms experienced during this disease. So what does ME/CFS really look like? If you are correctly diagnosed under current guidelines (I am using the International Consensus Criteria and IOM report as an example here), as well as profound and prolonged fatigue which is unalleviated by rest and lasts more than six months, you will experience:

  • Post-exertional neuroimmune exhaustion (a disproportionate physiological response to exertion, which can be delayed and last for hours, days, weeks or months after the event)
  • Neurological abnormalities such as cognitive impairment, delayed reactions, short-term memory loss, abnormal sleep patterns, headaches
  • Neurosensory and perceptual disturbances such as a sensitivity to light/sound/touch or the inability to focus vision
  • Motor impairments such as ataxia, pain, poor coordination
  • Immune symptoms (unrelenting flu-like symptoms)
  • Gastrointestinal complaints
  • Cardiovascular dysfunction such as POTS and OI (inability to maintain regular blood pressure and heart rate upon standing)
  • A one in four chance of being wheelchair-, house- or bed-bound
  • worse quality of life than those with conditions such as kidney failure, heart disease or MS and more equivalent to terminal cancer or stroke

This is just a short summary – the complexities of ME/CFS are too much to describe in great detail in this forum. Suffice to say, the symptoms are a great deal more than just “fatigue!”

Two images left is a young man smiling and waving at camera Right is same man emaciated in bed having his head shaved by his father

Above: Whitney Dafoe, one of the many faces of ME. From healthy travel photographer to bedridden and paralyzed.

If you wish to learn more about the true nature of ME/CFS, the International Consensus Primer is a good place to start. It was written by a team of specialists in the field specifically to address the confusion between patients with ME and those with other forms of fatigue, and narrow an overly-inclusive criteria which mixed the two.

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Thinkstock photo via Kerkez.

Originally published: May 24, 2017
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