Hello, I'm interested in learning more about how one can distinguish between POTS (or another variant of dysautonomia) and ME/CFS, and how a doctor could determine whether a patient had one vs. the other condition. The symptoms required to diagnose ME/CFS (using Canadian Consensus as an example) are almost entirely overlapping symptoms that could be attributed to POTS as far as I can tell. (And that's not accounting for POTS fulfilling the 'Autonomic Manifestations' criteria in CCC). The only difference I see is that in ME/CFS, the cardinal symptom is referred to as "PEM" whereas I hear "exertion intolerance" more frequently when reading about POTS. It is hard for me to distinguish even between these two symptoms, as I have heard "exertion intolerance" used to refer to the delayed symptoms that appear after exercise in POTS literature. Some people may have POTS only, and some people may have ME/CFS AND POTS, but how might one be diagnosed as having POTS but not ME/CFS?