Is 'Sickness Behaviour' a better term than 'Malaise'?

Are your PEM symptoms better described as post-exertional sickness behaviour?

  • Yes

    Votes: 3 16.7%
  • No

    Votes: 8 44.4%
  • Most Definitely Not

    Votes: 7 38.9%

  • Total voters
    18

Wishful

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In the thread about the difficulty of describing fatigue, someone mentioned that everyone hates the word 'malaise'. It's vague, I assume clinically unmeasurable, and linked to misperceptions (maybe confused with 'malingering'). Is PEM more accurately described as post-exertional sickness behaviour? I've included the definitions below.

Wiki: 'Sickness behavior is a coordinated set of adaptive behavioral changes that develop in ill individuals during the course of an infection.[1] They usually (but not necessarily)[2] accompany fever and aid survival. Such illness responses include lethargy, depression, anxiety, malaise, loss of appetite,[3][4] sleepiness,[5] hyperalgesia,[6] reduction in grooming[1][7] and failure to concentrate.[8] Sickness behavior is a motivational state that reorganizes the organism's priorities to cope with infectious pathogens.[8][9] It has been suggested as relevant to understanding depression,[10] and some aspects of the suffering that occurs in cancer.'

Miriam-Webster: 'Malaise definition is - an indefinite feeling of debility or lack of health often indicative of or accompanying the onset of an illness.'

My PEM certainly makes me want to curl up and wait for it to pass. Part of it can certainly be considered malaise, but there's also pain and lack of interest in things, so sickness behaviour seems to fit better. Since the medical community might accept 'sickness behaviour' as a valid symptom more readily than 'malaise', maybe a change of term is worthwhile. Yes, it's just a change of term, but that term can have major influence on how a doctor interacts with a patient.

For the poll, I'm most interested in seeing whether there are many people who feel the sickness behaviour definitely doesn't describe their PEM symptoms.

I also came across some papers stating that sickness behaviour is caused by cytokines in the brain, with different cytokines having different effects. That seems to fit ME, with people having different levels of individual sickness behaviours, likely due to different neuroimmune responses.


I do admit that PESB is unfortunately harder to pronounce. :rolleyes:
 

S-VV

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My pem is lactic acid driven. My lymph nodes also swell, but oxidative metabolism problems are my #1 symptom
 

Hip

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Part of it can certainly be considered malaise, but there's also pain and lack of interest in things, so sickness behaviour seems to fit better.
Yes, although PEM is the common name for these post-exertional symptoms of ME/CFS, malaise is only part of the story.

In the Canadian consensus criteria, regarding the post-exertional symptoms, they say:
There is an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability, post exertional malaise and/or fatigue and/or pain and a tendency for other associated symptoms within the patient’s cluster of symptoms to worsen.
See the 7 boxed criteria on page 2 of the CCC.

So the post-exertional symptoms may include malaise, but also may include worsened fatigue, pain, and a general worsening of all ME/CFS symptoms.
 

Pyrrhus

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‘Sickness Behavior’, as the term is commonly used, more properly refers to what we would call ‘flu-like symptoms’.

Although I sometimes get ‘flu-like symptoms’, they are quite different from PEM symptoms, although there may be some overlap.

The International Consensus Criteria suggested the term PENE, which stands for ‘Post-Exertional Neuroimmune Exhaustion’. Not a bad term, although the acronym PENE does mean ‘penis’ in some Latin languages.

I often like to suggest the term PESA, which stands for ‘Post-Exertional Symptom Amplification’. Not that we really need yet another term...
 

Wolfcub

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‘Sickness Behavior’, as the term is commonly used, more properly refers to what we would call ‘flu-like symptoms’.

Although I sometimes get ‘flu-like symptoms’, they are quite different from PEM symptoms, although there may be some overlap.

The International Consensus Criteria suggested the term PENE, which stands for ‘Post-Exertional Neuroimmune Exhaustion’. Not a bad term, although the acronym PENE does mean ‘penis’ in some Latin languages.

I often like to suggest the term PESA, which stands for ‘Post-Exertional Symptom Amplification’. Not that we really need yet another term...
I quite like that...‘Post-Exertional Symptom Amplification'
Rather than "Sickness Behaviour"
It's probably just my own turn of mind but to my view when the word "behaviour" is used, it sounds a little like a psychology term, or could be construed as such.

Personally what happens to me is I just get a return of the initial symptoms, sometimes almost as bad as they were when it all started, but most times now, a little milder. But still unpleasant.
This does however, have a mental/emotional effect, as when symptoms return, I get a sinking feeling. I thought I was better! And here it comes all back again! Like an inescapable situation.

And my "return of symptoms" is not necessarily provoked by physical exercise. It can be provoked by a period of lack of sleep, and/or unusual stresses in lifestyle (even strong weather changes) BUT, when I have it, physical exercise exhausts me and makes everything worse. I am not sure if mine is PEM in the true sense of the word....I don't know, as it is hard to pin down and seems a bit atypical compared to others.
 

junkcrap50

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I think a lot of people here confuse "malaise" with PEM, "post-exertional malaise." Exertion is not necessary to have malaise. It often triggers it, but everyone jumps straight to PEM. Malaise is my biggest symptom and often not caused by anything.

‘Sickness Behavior’, as the term is commonly used, more properly refers to what we would call ‘flu-like symptoms’.

Although I sometimes get ‘flu-like symptoms’, they are quite different from PEM symptoms, although there may be some overlap.
Malaise is a large part of flu-like symptoms. It's the general "I don't feel well" feeling one gets when sick, even if they don't have any clear-cut symptom like headaches, sore throat, stuffed nose, nausea, diarrhea.
 

duncan

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"sickness behavior" is a dangerous label. It was crafted for animals that could not communicate. We can.

As for malaise, it is a shit-word that means what anyone wants it to.

We need to appreciate specifics and nuance because sure as you're born they do.
 
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percyval577

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I think it´s not a description but an interpretation.
And as an interpretation I find it pretty descent - and, yes, a good idea to get the message across.
It´s more ambitious than the PEM which in its origin only describes the appearance ("after exercise you feel bad, wrong").
But its also not complete because it isn´t announced that it can appear delayed.
Only an immediate response we would expect from a "feel/behave sick" response.

---
In respect of doctors I guess they will tend to make up their own opinion on you if you come up with it:
"Another patient who knows a bit too much from all that internet rubbish,
instead it´s me who has learned all the stuff by heart."
And probably nothing is better compared to tell how you are doing.
 
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Wolfcub

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I think a lot of people here confuse "malaise" with PEM, "post-exertional malaise." Exertion is not necessary to have malaise. It often triggers it, but everyone jumps straight to PEM. Malaise is my biggest symptom and often not caused by anything.



Malaise is a large part of flu-like symptoms. It's the general "I don't feel well" feeling one gets when sick, even if they don't have any clear-cut symptom like headaches, sore throat, stuffed nose, nausea, diarrhea.
I completely understand this. It is what happens to me.
 

Wolfcub

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"sickness behavior" is a dangerous label. It was crafted for animals that could not communicate. We can.

As for malaise, it is a shit-word that means what anyone wants it to.
I feel that way about the "behaviour" word too.
Malaise is non-specific also. I remember trying to describe the return of symptoms and how I felt, to someone who was empathetic to the ME/CFS thing; "It feels like flu" I said....."Malaise perhaps"... They still couldn't quite get what I meant to describe. They thought "flu" had to mean coughing, runny nose, aching muscles (which I don't get) But I was trying to describe that feeling you get the first day you are starting with flu; a general horribleness!
 

percyval577

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Then it actually is a sickness response.
I think this is rather the implication of the term, it shall be a codified response.

As far as I know it has been coined originally for infections (precisly: for a response of the organism to an infection).
I am not so sure that it is restricted to it, the guessed code might work eg too if the organism is heavily wounded.

If I remember right, later the idea has been used to explain depression, so far of course with no results.
This is logical interesting because depression would be an ill "sickness response" (say in parts).
This might also apply for mecfs, and it could explain why the symptoms can get so severe.

In my opinion this codified sickness response that makes the organism feel sick and behave sick
would involve many pathways of different origin (immunesystem, CNS).
 

Wishful

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"sickness behavior" is a dangerous label. It was crafted for animals that could not communicate. We can.
In the case of ME, we're animals who can't communicate the details of our symptoms much better than any other animals. It's at least a term that is somewhat understood and accepted: cytokines in the brain cause certain changes, with reasonable consistency. If 'behavour' isn't acceptable, 'response' might be better (it hadn't come to mind when I first posted).

If I had to discuss my symptoms with a new doctor, I'd say that it seemed to be sickness behaviour rather than malaise. I think it would be more likely to get a positive response.
 

Wishful

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My pem is lactic acid driven. My lymph nodes also swell, but oxidative metabolism problems are my #1 symptom
Are you 100% sure that your PEM is driven by lactic acid? Have you tested this by ingesting/injecting lactic acid without exercise, and measuring your cytokine levels to make sure that they aren't changing at the same time? To me, exercise triggers all sorts of chemical responses in the body, and it would be very difficult to identify which one is responsible. Maybe lactic acid is a trigger for you, but I suggest keeping an open mind about other possibilities. I'm quite convinced that most of my symptoms are due to excess kynurenine production, but if strong counterevidence shows up, I'll switch my beliefs.
 

S-VV

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Are you 100% sure that your PEM is driven by lactic acid? Have you tested this by ingesting/injecting lactic acid without exercise, and measuring your cytokine levels to make sure that they aren't changing at the same time? To me, exercise triggers all sorts of chemical responses in the body, and it would be very difficult to identify which one is responsible. Maybe lactic acid is a trigger for you, but I suggest keeping an open mind about other possibilities. I'm quite convinced that most of my symptoms are due to excess kynurenine production, but if strong counterevidence shows up, I'll switch my beliefs.
I have not injected lactic acid. I have, however measured post exertional lactate, and it presents with two very pronounced peaks, climbing to 10 mMol/L

A doctor with CFS measured his lactate and got the same double peak pattern.

https://sciforschenonline.org/journals/neurology/JNNB-1-112.php

That being said, I have no doubt that the increased lactate is due to PDK upregulation caused by persistent inflammation, and that addressing this inflammatory loop without immune suppresion is a good way forward.
 

S-VV

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Sodium DCA, which is used in the treatment of congenital lactic acidosis helps me, so I believe that lactate/ oxphos is responsable for a big part of the symptoms.
 

Wishful

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If your lactic acid is due to increased immune system activation, then I'd say that your PEM is also due to that activation, and the lactic acid is a side effect. Maybe reducing lactate levels has an effect on the immune system, at least for some people.