This happens sometimes, it usually goes within half an hour.
I have generally low blood pressure and a low resting heart rate of about 60. Today at the end of DDs swimming lesson I stood up and suddenly felt it speed up. It's been at around 100 since then. Feels a bit weird.
It was very hot in there, I had been rushing around and the kids were being a bit annoying, but I wouldn't say I was overly stressed. Certainly I have been at that stress level many times without this happening! I had eaten fairly recently so not low blood sugar. Haven't had enough sleep this week though (staying up late mainly, not insomnia).
I've been sitting on the sofa