Yep, flu like symptoms are constant for me. But every now and then, when I'm having what I call a flare, the pain gets pretty intense. I would rate it at about a 7-8. It migrates. Today it's in a new and different place than usual. My knee. I never have pain there but today.. its really bugging me. I usually have pain in my hands wrists, lower back, neck, shoulders, headache, chest, and of all the weird places - arm pits (almost like I've been lifting barbells - sheesh just the thought of lifting barbells make me shiver!!).
So long a short of it, the fatigue causes a lot of the pain and if I don't listen to my body it causes a big time flare.
Hope that helps a little.