What's your first/last sign of PEM?


To put my data-science lessons to work, I'm trying to develop an early-warning system for PEM. I would appreciate others' input:

For some of us, there's a delay between overexertion (or whatever the trigger is) and the onset of full PEM. In my case, it's often 36-48 hours before the huge increase in pain, weakness, and exhaustion make it clear that I'm in PEM. I'm pretty sure that I would suffer less if I started resting during that mystery period of 36-48 hours, which I call 'early PEM.'

If you also experience a delay before full PEM sets in: 1) have you noticed any changes during the period of delay that make it clear that you've triggered PEM? For example, I used to burp a lot during early PEM.

Also, there's a similar period, which I call 'late PEM,' when I feel fairly normal until I engage in some light activity. This overexertion ends up deepening and extending my suffering. So I also wonder: 2) Do you have a clear sign that PEM has completely ended? What's your last symptom to go away?

Currently, I'm just trying to find an easy - possibly automated - way to diagnose 'early' and 'late' PEM. Some of this effort is for class projects, and partly it's just a self-interested hobby. If it works, then the goal is to turn my method into some sort of app.


New Member
I have moderate PEM-but it’s an everyday thing & directly related to quality of sleep.

I find hydration makes a real difference. Early signs are thirst & tired eyes. Scratchy sore throat is sign I really need to take extra immediate HORIZONTAL down time or I’ll be sick for days. Important to be highly sensitive, as PEM often doesn’t hit until I slow down (especially w/ holidays, traveling or special events) & then I’m down for weeks. Keto diet has helped with energy, but not pain.


I agree totally; I get what you call early PEM and then, towards the end, late PEM. Early is approx the first 24 hours after over-exertion. At this point, I feel weak throughout my body, the ringing in my ears gets much louder and shriller, I feel very cold, I get chest pain, my balance gets a little off, and I start to ache with nerve pain. If I rest at this stage, sometimes I can avert things from worsening. Usually, however, full PEM hits me at around 36 hours. It lasts for a variable length of time, depnding on factors such as how rested I was prior to the over-exertion, and how much I am able to rest during PEM. During PEM, my sleep is disrupted, I feel as if I'm running a fever, I have nerve pain, my brain is foggy etc etc etc. Then the symptoms begin to lessen in intensity (late PEM). At this stage, as you noted, it's very hard not to over-do things because 1) I am starting to feel better, and 2) I am getting behind with my chores and work. So this stage is marked by weakness; when I start resuming activities, I have very low stamina, and can easily retrigger everything. When I retrigger, the same symptoms begin to repeat. So the challenge during late PEM is to act as though I am still in PEM and keep resting.


New Member
First - Sudden deep ringing in only ONE ear. If I listen I can normally avoid PEM entirely.

Last - Lots of muscle spasms (not painful).


New Member
Definitely one thing is my balance problems getting worse, another is hitting that brick wall of cognitive dysfunction

Get Our Free ME/CFS and FM Blog!

Forum Tips

Support Our Work



Latest Resources