I get a lot of people asking me if their fatigue symptoms might be ME/CFS. Some I think yes, others no. How do I know?
There are a lot of conditions that cause similar symptoms at the time of activity (including idiopathic CFS), like shakiness, nausea, irritability, pain, neurological problems etc, and many have delayed recovery times, but the defining characteristic of ME vs Anything and Everything else is a thing called Post Exertional Malaise (PEM).
Like everything else about this illness, it’s poorly named, often misunderstood, and makes no sense. It is NOT the same as being tired and taking a long time to recover from a big day.
PEM is a delayed response, so you may feel fine at the time of the activities and even for a few days after (it took a couple of weeks for my wedding to catch up with me). It’s that time between charging the credit card and having to pay the bill where you feel like you still have money (which also increases the risk of over spending on your energy budget in that time). Once it hits, it’s like getting the flu or some other major viral infection. You aren’t ‘tired’, you’re Sick, often Very Sick.
It usually takes at least 24 hours to kick in, but it can depend a lot on how far you pushed – if you’ve driven yourself to a ‘collapse’ state, you may not have recovered from that before the PEM hits, other times you might get a migraine in the evening because you had a busy morning, but the most common timeframe seems to be 24-48 hours after activity.*
PEM isn’t fatigue, or tiredness, despite the name, it’s a full body neurological inflammation and metabolic shut down. It’s being seriously ill.
You might be too weak to stand, have flu like symptoms (sore throat, ache all over, even elevated temperature), or you may be vomiting with migraine symptoms, or you might lose the ability to speak or read or something like that. You may be crying uncontrollably for an unknown reason (as in, you don’t feel like crying but your body is doing it anyway).
The symptoms will not usually reflect the activity that brought them on (i.e. an emotional experience may cause a sore throat or muscle and joint pain and weakness in the limbs, while going to the gym might cause stomach upsets, light sensitivity and an inability to speak). You may have a mild fever, struggle to breathe, and be winded from a day of intense decision making and problem solving. The responses with differ between people and the activities that trigger them.
PEM generally lasts a long time, and can even cause the body to decline permanently, so pushing too hard too often will reduce your ability to push at all. Whole systems of the body can fail through sustained metabolic failure and nerve inflammation.
Which means triggering PEM is like a game of Russian roulette, where you don’t know if you will recover this time or be permanently this weak and sick now.
PEM as Energy Bucks
Thinking back to my Energy Bucks model, the potentially permanent effect of PEM suggests that ME doesn’t have an external source of energy income, but is the income generated from the interest on a large savings account or investment portfolio.
My body is a cash portfolio that generates interest for me (interest rates can vary depending on the food I put in but are mostly pretty low and fixed). If I get EB$100 per day in energy interest but I spend EB$150, then I will either go into debt (and have to pay interest on that loan) or withdraw a little from the savings principal. In the short term, withdrawing a little more than I earned isn’t a big deal, because I can just rest for the next week, using EB$90/day, and rebuild the principal to where it should be. If I can keep that up for long enough, I may even save enough to give me more interest to live on… but getting enough savings together to increase my standard of living is close to impossible…
As I said in the original energy bucks post, the energy budget is tight. So the slightest extra drain on our resources can put us well over budget, and complete rest, without stimulation and requiring minimal metabolic activity is impractical for most people.
So if I consistently go over budget, or go too far over in one go, I eat away at the principle. This reduces the interest I can now earn, so instead of having EB$100/day to live on, I have EB$90, EB$80 or EB$50, which makes those EB$150 days even harder to fund.
Continually going into PEM or going too far into PEM has the potential to reduce that nest egg, and the interest paid, until it doesn’t even cover the very basics of bodily rent, the Basal Metabolic Rate. This is when tube feeding, hydration through a j-tube, complete isolation in a climate controlled room without sensory input etc becomes necessary just to survive… imagine what might happen to their savings account if that person with ME now tried to walk…
Addendum and clarification
I know I’ve repeatedly stated that the good/bad news is that ME doesn’t kill you… that is and isn’t true. There are people who have died from ME, but in every case it was because they were forced to keep drawing on that principal well after the interest paid was too low to sustain their body. For most of us, not in the “care” of physicians who believe we can exercise ourselves better, we decline until we’re forced to stop, or we learn to live within our meagre means. The difficulty involved in (the unassisted) reduction of interest to that point where we can’t even stay alive without help means it tend to be self limiting, to a point.
* You may also get these symptoms while doing the thing, but there will also be a bill to pay later too