I have no medical background, but taking a guess I would say, if your heart rate goes up while exercising, then that’s a normal bodily reaction – it’s expected.
If your heartbeat goes faster due to drugs -unexpectedly – you might think you’re having a heart attack, panic over it, get it to increase even more due to the panic, and actually get a heart attack. This is why you never ever ever slip anyone drugs without them knowing.
Latest Answers