How Stress Makes You Sick
When Stress Is Good
The stress response originates in our heads or, more precisely, in the hypothalamus, a section of the brain that regulates blood pressure, body temperature, respiration, sleep-wake cycles, hunger, and sexual function. The hypothalamus has another job: to survey our surroundings for danger and prepare us to fight or flee. It does this by sending out a warning to the adrenal glands, which in turn flood the bloodstream with adrenaline. This hormone increases our heart rates and sends blood to our muscles and extra oxygen to our brains to keep us alert. At the same time, our brains secrete natural painkillers, known as endorphins, to help us withstand injuries we may incur. The hypothalamus also sends a substance to the pituitary gland in the brain, which triggers the adrenal glands to make the stress hormone cortisol, which releases glucose and fatty acids for extra energy. This whole process may take only a few seconds.Under life-or-death conditions, all this is beneficial, as when, for example, a mother needs to rush into the street to scoop her child from the path of an oncoming car. But can stress be good on a more regular basis, too? Absolutely, says Dr. Sternberg, author of The Balance Within: The Science Connecting Health and Emotions (W.H. Freeman & Co., 2001). We need those extra jolts of adrenaline to achieve peak performance in our daily lives. Unlike animals, however, humans also face psychological stressors. Whether they are imminent (such as difficulty paying the rent or mortgage) or longer-term (a child not doing well in school), the stress hormones rush to our aid. If our internal feedback system is working properly, when the threat or our stressful thoughts about it have passed, our adrenals send a message back to the hypothalamus telling it to stop producing excess cortisol and adrenaline.Many of us, however, are so overwhelmed by stress that the circuit doesn't stop. Too much of a good thing turns bad, and these chemicals act like a poison, which can then negatively affect our health.