Your Brain and Body on Stress

Smart Stress, Dumb Stress

You are what you think. More correctly, you are what you let yourself think. In this article, you will learn how you can change your brain by changing your thoughts. Let’s take a closer look at when stress is smart, and when it is not.

Your Brain and Body on Smart Stress

Suppose the fire alarm goes off. You awaken, and your stress hormones dial-up to high alert. Why? Because the well-being of your family depends upon your making quick, life-saving decisions. Your SNS tells your blood pressure and heart rate to increase to pump more blood to your brain, heart, lungs, and muscles while shunting blood away from your gut, kidneys, and reproductive organs. You don’t have time to eat, pee, or procreate while your house is burning. You grab the kids and, if time permits, your prized possessions, and you safely run out of the house, escaping the fire.

You take a deep breath, think something like, “Thank God we’re all safe,” and your stress hormones dial back down. The next day you get on with the repairs, still thinking about how fortunate you are to have survived unharmed.

This is a normal and healthy stress response.

stress and the brain

Not Smart Stress

Suppose, however, that after you escape the fire, your stress dial stays high. You continue to worry: “If only I had . . . ” “What  if it happens again?” “Why me?” The worry drags on for days and weeks. Your stress hormone dial stays up and the stress effects of high blood pressure and high heart rate stay high. When stress hormones stay too high for too long, instead of helping the brain, they damage it. This process is called glucocorticoid neurotoxicity (GCN). Translation: “Hey, high-stress hormones, you’re wearing me out!”

Don’t Worry, Be Happy: How Stress Bothers Your Brain

Stress hormones are somewhat like blood sugar. Our brain needs just the right level to function: too low and the brain gets too tired; too high and the brain gets inflamed and damaged by sticky stuff. The same is true for stress hormones. Too high and it can cause inflammation; too low and it can lead to depression. The right level is biochemically good for the brain.

Stress hormones go by various names, such as cortisol, corticosteroids, glucocorticoids, epinephrine, norepinephrine, and many others. We’ll mainly discuss the stress hormone cortisol, because it’s the most common and best known, but know that it’s really not accurate to blame all of our stress responses, and their consequences in the brain, on this one hormone.

How Worry Shrinks the Brain

Prolonged high levels of cortisol can literally shrink the memory and emotional centers of your brain. This is why the worst thing you can do when going into an important presentation is to be overstressed because it can neurochemically shut off the memory bank that you need to draw on to give it your best. While the right level of cortisol increases alertness and attention during a work task or while taking a test, stress hormones that are too high for too long dull focus. Your mind can “go blank.” It’s that glucocorticoid neurotoxicity again.

Why Stress Makes you Tired

Wonder why stressed and anxious people often suffer “chronic fatigue”? When you experience a stressful situation, your lifesaving stress hormones (especially the fast-acting adrenaline rush) quickly withdraw fuel energy from your body’s energy storage bank (stored sugar and sometimes fat) and deliver it to the brain and muscles for quick decisions and fast movement. But once your stress dial turns back down, those hormones stop withdrawing the energy, and your body has the chance to build its energy stores back up.

When this stress dial stays turned up too high for too long, continuously calling on its buddy, the adrenal gland, to produce more cortisol, your energy bank eventually goes broke. You get sick and tired, something called adrenal fatigue.