My CFS has always been very intwined with dysautonomia. While there have definitely periods when I've been in CFS states (total crashes) I've also had extended periods where it's really hard to tell where the CFS ends and the POTS begins. I've been healthy for a couple of years, but in April I started to have OI symptoms, and they've been going off and on with varying degrees of severity and disability since then. I was diagnosed (again) with POTS after a tilt in June, and everything that's been happening can--from a diagnostic standpoint--be explained by that, even some fatigue. (It's very convenient.) Except that nothing helps the POTS. For the last month or so my blood pressure has been low to extremely low, and I'm this curious off-white color. So, my CFS doctor just suggested that it all might be hypovolema (low blood volume) instead of POTS--rather that while they are POTS symptoms, the mechanisms might be different. The Googles show there's a bit of a data on this in CFS (As much as there is on anything) and Dr. Bell's done some work on it. Does anyone have any thoughts or experience?