I guess Dr Diana, that the diagnosis of POTS is not straight forward. I was told by my rheumatologist, a well known one in the EDS world, that I very probably have POTS. He did a lie to stand test (not quite poor man as it wasn’t long enough) but I did have an increase in heart rate very quickly by 23bpm, with no BP change, although it was via a regular cuff, not a continuous monitor (so perhaps the exact rise wasn’t known). However, a lot of the specialist centres (e.g.: Vanderbilt) seem to think that the increase of 30bpm+ needs to be sustained for at least 10 minutes for POTS to be diagnosed. The guidelines seem to be very specific to avoid over diagnosis don’t they. The initial heart rate spike can vary between (non pots) individuals naturally, it is if the spike is maintained or elevates more that is significant. In some it seems obvious, such as in hyperadrenergic POTS. I guess the point i am making is that just because you fall short of traditional POTS criteria doesn’t mean the EDS isn’t making you pretty ill!! You still have dysautonmia, which incidentally, like a lot of medical problems, must be a spectrum disorder mustn’t it? Therefore the mechanisms causing the autonomic type symptoms in EDS are no different whether you fulfil the POTS diagnosis or not. I feel it is important to state that, to avoid people trivialising symptoms and people just falling by the wayside. These individuals (me, possibly) would still benefit from treatment with Diamox, and other treatments you might have lined up based on your revised theories…. Look forward to hearing about it….