They are natural chemicals which our bodies would normally produce in response to various stressor, so one can't avoid them, they are designed to be there and necessary. In fact if you ever woke up around 3 or 4 in the morning, it was your body giving you a little jolt to start waking you up with the dawn. Bad dreams of fighting, pursuit, etc. are probably triggered the same way, or maybe they do the triggering. This could be why so many sudden deaths occur in sleep.
They are natural chemicals which our bodies would normally produce in response to various stressor, so one can't avoid them, they are designed to be there and necessary. In fact if you ever woke up around 3 or 4 in the morning, it was your body giving you a little jolt to start waking you up with the dawn. Bad dreams of fighting, pursuit, etc. are probably triggered the same way, or maybe they do the triggering. This could be why so many sudden deaths occur in sleep.