Stressors are what activate the stress response in your body. They can be anything you see, hear, smell, touch, taste, or imagine could do you harm. There are external stressors: work, money, family, time, cultural norms and expectations, experiences of discrimination, and so on. And there are less tangible, internal stressors: self-criticism, body image, identity, memories, and The Future. In different ways and to different degrees, all of these things may be interpreted by your body as potential threats.
Stress is the neurological and physiological shift that happens in your body when you encounter one of these threats. It’s an evolutionarily adaptive response that helps us cope with things like, say, being chased by a lion or charged by a hippo.1 When your brain notices the lion (or hippo), it activates a generic “stress response,” a cascade of neurological and hormonal activity that initiates physiological changes to help you survive: epinephrine acts instantly to push blood into your muscles, glucocorticoids keep you going, and endorphins help you ignore how uncomfortable all of this is. Your heart beats faster, so your blood pumps harder, so your blood pressure increases and you breathe more quickly (measures of cardiovascular functioning are a common way researchers study stress).2 Your muscles tense; your sensitivity to pain diminishes; your attention is alert and vigilant, focusing on short-term, here-and-now thinking; your senses are heightened; your memory shifts to channel its functioning to the narrow band of experience and knowledge most immediately relevant to this stressor. Plus, to maximize your body’s efficiency in this state, your other organ systems get deprioritized: Your digestion slows down and your immune functioning shifts (measures of immune function are another common way researchers study stress).3 Ditto growth and tissue repair, as well as reproductive functioning. Your entire body and mind change in response to the perceived threat.
And so here comes the lion. You are flooded with stress response. What do you do?
You run.
You see, this complex, multisystem response has one primary goal: to move oxygen and fuel into your muscles, in anticipation of the need to escape. Any process not relevant to that task is postponed. As Robert Sapolsky puts it, “For us vertebrates, the core of the stress-response is built around the fact that your muscles are going to work like crazy.”4
So you run.
And then?
Well, then there are only two possible outcomes: either you get eaten by the lion (or trampled by the hippo—in either case, none of the rest of this matters) or else you escape! You survive! You run back to your village, the lion chasing you all the while, and you shout for help! Everyone comes out and helps you slaughter the lion—you’re saved! Yay! You love your friends and family! You’re grateful to be alive! The sun seems to shine more brightly as you relax into the certain knowledge that your body is a safe place to be. Together, the village cooks a lot of the lion and shares a communal feast, and then you all bury the parts you can’t use, in an honoring ceremony. Hand in hand with the people you love, you take a deep, relaxing breath and give thanks to the lion for its sacrifice.
Stress response cycle complete, and we all live happily ever after.
Just Because You’ve Dealt with the Stressor Doesn’t Mean You’ve Dealt with the Stress Itself
Our stress response is beautifully fitted to the environment where it evolved. The behavior that dealt with a lion was the behavior that completed the stress response cycle. And that makes it easy to assume that it’s the elimination of the lion—the cause of the stress—that completed the cycle.
But no.
Suppose you were running away from the lion, when it’s struck by lightning! You turn and see the dead lion, but do you suddenly feel peaceful and relaxed? No. You stop, puzzled, heart pounding, eyes darting in search of the threat. Your body still wants to run or fight or hide in a cave and cry. The threat may have been dealt with by an act of God, but you’re left still needing to do something to let your body know you’re safe. The stress response cycle needs to complete, and just eliminating the stressor isn’t enough to do that. So maybe you run back to your village and breathlessly tell your tribe what happened, and you all jump up and down and cheer and thank God for the lightning bolt.
Or a modern example: Suppose the lion charges—it’s coming right for you! Adrenaline and cortisol and glycogen, oh my! And so, thinking quickly, you grab your rifle and shoot the lion, to save your own life. Bang. The lion drops dead.
Now what? The threat is gone, but again your body is still in full action mode, because you haven’t done anything your body recognizes as a cue that you are safe. Your body is stuck in the middle of the stress response. Just telling yourself, “You’re safe now; calm down,” doesn’t help. Even seeing the dead lion isn’t enough. You have to do something that signals to your body that you are safe, or else you’ll stay in that state, with neurochemicals and hormones degrading but never shifting into relaxation. Your digestive system, immune system, cardiovascular system, musculoskeletal system, and reproductive system never get the signal that they’re safe.
But wait, there’s more:
Suppose the stressor is not a lion, but some jerk at work. This jerk will never be a threat to our lives, he’s just a pain in the ass. He says some jerky thing at a meeting, and you get a similar flood of adrenaline and cortisol and glycogen, oh my.5 But you have to sit there in that meeting and be “nice.” “Socially appropriate.” It would only escalate the situation if you vaulted across the table and scratched his eyes out, as your physiology is telling you to do. Instead, you have a quiet, socially appropriate, highly functional meeting with his supervisor, in which you recruit the supervisor’s support in intervening the next time the jerk says another jerky thing.
Congratulations!
But addressing the cause of the stress doesn’t mean you’ve addressed the stress itself. Your body is soaked in stress juice, just waiting for some cue that you are now safe from the potential threat and can relax into celebration.
And it happens day after day…after day.
Let’s think about what this does to just one system, the cardiovascular: Chronically activated stress response means chronically increased blood pressure, which is like constantly turning a firehose on in your blood vessels, when those vessels were designed by evolution to handle only a gently flowing stream. The increased wear and tear on your blood vessels leads to increased risk for heart disease. That’s how chronic stress leads to life-threatening illness.
And this happens, remember, in every organ system in your body. Digestion. Immune functioning. Hormones. We are not built to live in that state. If we get stuck there, the physiological response intended to save us can instead slowly kill us.
This is the upside-down world we live in: in most situations in the modern, post-industrial West, the stress itself will kill you faster than the stressor will—unless you do something to complete the stress response cycle. While you’re managing the day’s stressors, your body is managing the day’s stress, and it is absolutely essential to your well-being—the way sleeping and eating are absolutely essential—that you give your body the resources it needs to complete the stress response cycles that have been activated.
Before we talk about how to do that, let’s talk about why we aren’t already doing it.
Why We Get Stuck
There are lots of reasons why the cycle might not complete. These are the three we see most often:
1. Chronic Stressor → Chronic Stress. Sometimes your brain activates a stress response, you do the thing it says, and it doesn’t change the situation:
“Run!” it says, when you’re confronted by a terrifying project—speaking in front of a group of your peers, say, or writing a giant report or interviewing for a job.
So you “run,” in your twenty-first-century way: when you get home that day, you put on Beyoncé and dance it out for half an hour.
“We escaped the lion!” your brain says, breathless and grinning. “Self high five!” And you’re rewarded with all kinds of feel-good brain chemicals.
And then tomorrow…the terrifying project is still there.
“Run!” your brain says again.