#source: I have IST and it sucks and my symptoms are very similar to the symptoms people describe with POTS

[normal-with-adhd-is-a-joke]

I've seen a lot of people self-diagnosing with POTS recently which is very valid but it's worth mentioning that if your tachycardia is seemingly random (not associated with orthostatic changes) it could be a similar but less common condition called Inappropriate Sinus Tachycardia (IST). This is characterized by a heart rate of more than 100bpm at rest with no determinable cause. If you suspect you have IST but have a doctor who isn't a fan of self-diagnosis, I would recommend getting a finger pulse oximeter and taking your heart rate whenever you're feeling ill. Record it in a chart or journal and bring it in to your doctor. There is no cure but there are treatments like medication and reduction or removal of triggers like caffeine. I've also found deep pressure therapy, especially when provided by an animal, to be very helpful but I'm not sure about the science behind that.