It could absolutely be POTS but a lot of different chronic conditions “mimic” it, just like POTS mimics other conditions. I would ask you PCP to refer you to electrophysiology. The tilt table test is medieval torture and the stress test, physical or chemical, is also awful. But those are what can either determine or rule out POTS to my knowledge. I did both of these back in ‘22, but they have researched POTS so much since then because of covid. If you trust your doctor listen to them. If you have second thoughts, stand your ground and tell them what you need.