I have pots and my heart rate jumps up to 120 while I am walking which is not super high. But not great. While I sleep my heart rate will go down to 64, then shoot back up to 75-80 within 20 mins. And this happens over and over until I get up around 3-4 am and can't go back to sleep. When I was an active drinker in my 20's I used to get up around 3/4 am and then go back to sleep. I assumed it was sugar and had my blood sugar and pancreas and diabetes testing and everything came back normal. I also don't lack vitamins and minerals.