I’ve previously considered myself to be unlikely to have POTS. I can be almost normally active on very good days (paid for later). But a recent experience of tachycardia (110-135bpm when normal resting was 58-70) for days on end, and repeated instances in the days before and after that of sitting (hunched or reclining) with 70s bpm, stand (just calmly standing) and within a minute it’s over 120, up to 140s and a brief 150s... sounds like POTS. But it’s not always the case. Does that mean it’s not POTS? Or is it possible to have POTS only in PEM?