Hi, I'm a 14-year-old male and I was at school earlier today when my heart rate went up dramatically. It went up to about 250BPM and it went back to normal after about 5 minutes.

I have searched a bit about this topic and I have found that after drinking a lot of caffeine then in about an hour, you get this, but the problem is that I don't drink any coffee and I barely ever have energy drinks. Although 3 days before this I drank a fair bit of Mountain Dew Energized.

I don't have any disabilities except for anxiety but I wasn't anxious at the time

Thanks