Feeling stressed? Here’s what is actually happening

By Kate The Chemist,

Published October 29, 2024 at 9:47 AM CDT

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Stress is a natural part of life. It helps us survive and adapt.

But when it starts overloading our brains and we fail to cope with it in healthy ways, stress can cause serious health issues.

In the HBO documentary “One Nation Under Stress,” scientists explore the impact of stress and how it’s related to the cause of “deaths of despair,” i.e. those caused by drug and alcohol abuse, overdoses, suicide, and other underlying mental health issues.

The life expectancy in the United States is dropping faster than any other developed demographic in the world, and researchers like Dr. Rajita Sinha believe a leading culprit is mismanaged stress.

“We've gone back to the basics,” says Sinha. “We've gone back to say, why do I feel this, my chest popping out of me? And why do I feel my stomach in a clench for days? And what is that all about? Why do I get sad? Why am I slamming the door?”

Stress is something we all face and feel in different ways. That's why it has been a challenging topic for scientists to research. But new advancements in technology and MRIs have revolutionized stress research.

Sinha is a psychiatry and neuroscience professor and the founder of the Yale Stress Center. This innovative lab is using MRIs and other scientific instruments to look inside the human brain to figure out what’s happening when we’re feeling stress or anxiety. She says it’s been “revolutionary” for this area of research, “because everything before then was based on symptoms, based on what people described.”

That’s why stress has long been a challenging topic for scientists to research: Everybody feels it in such different ways.

“You might feel it in your chest,” Sinha says. “You might feel it in your stomach, your muscles, your face may change, your voice may change, what you say will change, the pressure of it.”

With emerging technologies and new focused research efforts, scientists are beginning to unwind the complicated code to understand why we feel stress in different ways and discover the tools we can use to help manage it.

So first, what is stress?

According to Sinha, “We have a robust biology of stress.”

She says stress is the experience of feeling challenged, pressured, threatened or overwhelmed, or the distress from any type of unpleasant experience.

Dr. Rajita Sinha is a psychiatry and neuroscience professor and the founder of the Yale Stress Center.

Physical stressors might be someone chasing or attacking you. But there’s also climate related stressors or internal pressures of feeling uncertain, a lack of control or having too much to do.

Your body also faces stress when you’re recovering from an illness or chronic pain, or if you’re the caretaker for a sick child or an elderly relative.

Is there a reason we experience stress?

“We are wired for survival, both individually to survive. But also for a species to procreate and to keep the species going,” says Sinha. “And one of the things that’s very critical and main function of the biological stress system is adaptation.”

Let’s say you go for a hike and then suddenly a bear appears. In that split second, your amygdala, the part of your brain that handles your emotions, will send an SOS signal to the hypothalamus, which alerts your nervous system to send a lightning-fast message to the rest of your body. That’s how we know to freeze, or run in an instant.

That’s the response we’ve come to call “fight or flight” or “tend or befriend.” But that’s only one part of the stress response, says Sinha. “That is not the only thing we do. We do a lot more than surviving.”

What does stress look like inside our bodies?

Research out of the Max Planck Institute of Molecular Cell Biology and Genetics shows that our cells know when we’re in a stressful situation, and they form “membrane-less compartments” that help us survive in the moment and then recover more easily after the stressor has been eliminated.

Dr. Rajita Sinha is the founder of the Yale Stress Center, where a team of scientists are using brain images and a multidisciplinary approach to collect stress data.

Common biological responses are fast heartbeats, headaches, or tightness in your stomach and muscles.

“But we also sometimes act out our stress,” says Sinha. “Whether you're slamming a door or you're running away from something. That's the behavioral side of it. And then there's the cognitive side.”

When our hypothalamus communicates with the rest of the body, it releases a molecule called the corticotropin-releasing hormone, which makes its way over to the base of our brain, right behind the bridge of our nose to find the pituitary gland.

And here, another molecule is introduced, the adrenocorticotropic hormone, which hustles down to our kidneys to find the adrenal gland.

This is when the stress hormone cortisol arrives, allowing for our bodies to stay on high alert until our perceived threat disappears.

To put this into perspective, people with Cushing syndrome have something called hypercortisolism — a condition where the chronic exposure to high levels of cortisol trigger neurological symptoms like muscle weakness or “difficulties with memory and concentration.”

Their higher levels of stress contribute to physical symptoms too, like weight gain in the face or the growth of a hump between their shoulders.

When kept in check, Sinha says these stress hormones can have a lot of different functions.

“They're part of our arousal biology, waking, sleeping cycle, our food intake responding to food, but they're also very, triggered and stimulated by stress,” she says.

Often the function and importance of cortisol gets misunderstood, and is incorrectly described as purely a bad thing.

“But let me tell you, none of us would be able to live without the stress hormone cortisol,” Sinha says. “Just like we would not be able to live if we did not have our stress biology. Acute increases in cortisol actually gets our immune system going and gets the immune system ready to fight disease, fight the viruses and microbes that we are all always being exposed to, whether it's breathing in or through our gut and other places.

“And so you want your cortisol rhythm to be really jazzed up and flexible and dynamic.”

Otherwise something called chronic stress can occur, and that can be really bad for you on a molecular level.

Often in stressful moments, humans instinctively look for a quick hit of dopamine (from alcohol, drugs, or food) to try to level out. But Sinha suggests that there are healthier stress-busters we should be trying instead.

To find out why chronic stress is so detrimental to human health, and which stress-busters Dr. Rajita Sinha recommends, listen to the latest episode of Seeking A Scientist.

Additional sources from Seeking A Scientist:

Seeking A Scientist is a production of KCUR Studios. It's made possible with support from the Stowers Institute for Medical Research, where scientists work to accelerate our understanding of human health and disease.

It's hosted by Dr. Kate Biberdorf, AKA Kate the Chemist. Our senior producer is Suzanne Hogan. Our editor is Mackenzie Martin. Our digital editor is Gabe Rosenberg.

This episode was mixed by Suzanne Hogan with support from David McKeel, Laura Spencer, Byron Love and Genevieve DesMarteau.

Our original theme music is by The Coma Calling. Additional music from Blue Dot Sessions.