I have CFS. My very good friend and internist did not want to dx it. But since he sees me at work, in his office, and very often in real life, he couldn't deny my symptoms. He is a doc who hates any kind of dx like fibromyalgia, etc. He doesn't believe in them. So I was surprised he actually agreed to treat me for it.
I had a span of time (still do) that I get sick very easily, had fevers with unknown etiologies and no other sx, and at one time went for blood work to check my levels of IgM, and other levels I don't recall, but he is very literate in reading the level of EBV. I was shown to have a very active EBV. Odd for my age. And I originally had "mono" when I was a teen. He has no idea why I still have such issues. He wanted to send me to an ID doc, but I have not gone, since I really don't want any more tests.
I just underwent a hysterectomy for a cancerous mass. I have a laundry list of medical issues, my most troubling right now being severe back pain (chronic x8 years), and my lupus.
Feel free to PM me if you'd like to talk more about it privately.