The sympathetic nervous system was thought to have evolved with jawed vertebrates. But lampreys—jawless, parasitic fish that suck out the blood of their hosts—have a simple one, per recent research.

Heart rate variability (HRV) typically increases with parasympathetic activation (rest-and-digest response) and decreases with sympathetic activation (fight-or-flight response). The autonomic nervous ...

Want to improve your health on a truly deep level? The practice of yoga—including pranayama (breath control) and meditation—has been proven to improve the function of the entire nervous system, which ...