What caused POTS

For those who are diagnosed with POTS, do you have another condition that doctors think may have caused you to develop POTS? Or, do you have POTS independent of any other condition?

I read that diseases like Lupus and Parkinson’s can result in people having dysautonomia generally. Is the same for POTS specifically?

I’m in my early 40s and I only recently (past year or so) began having symptoms of pre-syncope when I stand up, I almost black out about 50% of the time. It’s slowly getting worse too. If I bend down to pick something up, I get the same symptoms when I stand up straight again. I’m also getting occasional adrenaline dumps that are terrifying!

About 10 years ago I developed heart palpitations. I was finishing my education and preparing to study for the bar exam and find a job etc, so the cardio said it’s probably stress but let’s put you on a beta blocker. It also helps with my high heart rate and blood pressure. It worked great for me, until about a year ago. The palpitations have slowly returned and my high heart rate has returned too. So is it possible that I had a bigger issue 10 years ago that was just managed with the beta blocker and for some reason the beta blocker isn’t working for me anymore?

Or, is it more likely that I’ve developed Lupus, or something else, that’s causing these dysautonomia/POTS symptoms?