My crashes usually involve profound fatigue. I will spend most of my days on the couch and often feel weak. Lately I think I must be retracing because I have gone back to nausea, diarrhea, and some weight loss. But it's not as bad as it used to be and I can feel myself starting to come out of it. The crashes often last for several weeks at a time which is frustrating when I hear others telling of symptoms coming back for just a couple of days. But my husband experiences the same thing so I guess that's just how it goes for some of us.