"Say hello to cortisol, your body’s master hormone. It’s the friend that helped your ancestors flee predators in the African savannas. It’s the enemy, though, when it overreacts and hangs around too long – damaging every cell and biological process in your body. Cortisol is the body’s alarm system that makes your heart pound when you parachute out of an airplane or sit down to take a college entrance exam. It tells you to act now to save your life. But it can also send you into a panic over the stresses of everyday life: Abusive workplaces, job losses, money worries, and strained relationships to name a few"