I try to stay away from caffeine as much as possible I eat very healthy mostly vegetarian diet. I know a lot of younger people have slightly faster heart rates but going from a resting rate from 55 to 65 all the way to 100 to 110 is a little odd. I can still talk when its up to 200 just have a very odd feeling I guess. It is a little harder to breathe maybe I'm not sure and I'm not really up for trying it out again. Im kinda at a loss
You should be seen by your doctor to have your adrenal glands checked. If there is a kidney tumor, the symptom is fast heart rate. Otherwise, you could just have an adrenal problem in which exercise, black licorce or caffeine triggers the adrenaline rush and speed up your heart rate. It could be a lack of B vitamins or calcium. A lot of young people have fast heart rates that slow down with age. Are you able to talk when your heart rate goes up to 180 or 200? When a heart rate reaches 200, the heart is not working properly. You should really see your doctor regarding this.