I am bedridden 24/7 with severe M.E. I paid for a private doctor to visit me at home whom has an interest in autonomic dysfunction. I have orthostatic intolerance as a part of my M.E, I suspect POTS, but am too ill for proper testing. In his letter to my GP, he wrote 'the pathogenesis of ME/CFS complex is unknown and a spectrum disease, ranging from pure autonomic failure through to pure psychological problems'. I feel this statement is wrong but I am not intelligent enough to refute it. Can anyone share how one responds to such statements?