Our limbic systems evolved hundreds of thousands of years ago. The threats then were often immediately life-threatening: fear of starvation, becoming prey, and environmental changes that we could not control.
But today, our lives are full of so many "little" stressors—not to mention all the life-altering ones—our limbic system is working triple-time. Even changing careers, although a positive move, is considered a stressor to our limbic system.
Because our limbic system, by its own doing, is swimming in stress hormones because of life events, it becomes chronically overstimulated.
Chronic overstimulation of the limbic system has these effects on the body: