I don't think the framing of "real" or not is useful here - whether it maps to one or many underlying conditions (or even in the IMO unlikely event it always mapped to some other established condition), the symptoms are real for the people diagnosed with it, and unless there's a more useful set of criteria that match, it's reasonable to use as a shared descriptor.
A few years ago, I had a fun experience - all of a sudden, I was absurdly exhausted (not just "tired", but "physically could not reliably get out of bed sometimes") from the time I woke up to the time I went to sleep, independent of how much I was sleeping (or the quality of the sleep), or what I ate, or [...]. I didn't have headaches, or fever, or anything else, I was just perpetually exhausted.
As it turns out, I came back with a suddenly positive mono test where I had never had one before, and once a few weeks passed, it did too. But it gave me some reference for how it feels to be perpetually not just mentally but physically exhausted, with the potential of it never ending (since mono can have permanent repercussions, as someone I know discovered).
I think "post-viral syndrome" is the term getting traction now for "long COVID" and post-mono consequences and the like, but AIUI the criteria are the same save CFS not requiring an infection as a trigger event.
A few years ago, I had a fun experience - all of a sudden, I was absurdly exhausted (not just "tired", but "physically could not reliably get out of bed sometimes") from the time I woke up to the time I went to sleep, independent of how much I was sleeping (or the quality of the sleep), or what I ate, or [...]. I didn't have headaches, or fever, or anything else, I was just perpetually exhausted.
As it turns out, I came back with a suddenly positive mono test where I had never had one before, and once a few weeks passed, it did too. But it gave me some reference for how it feels to be perpetually not just mentally but physically exhausted, with the potential of it never ending (since mono can have permanent repercussions, as someone I know discovered).
I think "post-viral syndrome" is the term getting traction now for "long COVID" and post-mono consequences and the like, but AIUI the criteria are the same save CFS not requiring an infection as a trigger event.