It’s easy to think of stress as an occasional visitor—a passing storm cloud that scatters once the sky clears. But what if it’s more like a leak, seeping into your body, your mind, and even the people around you? Neuroscientist and best-selling author Dr. Tara Swart believes that stress is far more insidious than most of us realize. She spent her career untangling the complex ways our brains and bodies respond to stress, revealing insights that are as fascinating as they are vital to our health, relationships, and resilience.

Imagine this: you’ve just walked into a room to meet someone. By the time the conversation is over, you feel completely drained, as if their stress leapt from their body and coiled itself around yours. Dr. Swart says this isn’t just your imagination. Stress, specifically the hormone cortisol, can literally be contagious. It leaks from our sweat, wafting into the invisible space around us, and seeps into the skin of anyone nearby. It’s not just a metaphorical cloud hanging over someone’s head—it’s science. And while this might sound unnerving, the revelation is also empowering. Understanding how stress operates gives us a chance to disrupt its cycle.

Dr. Swart’s insights stem from a deep understanding of how the brain and body work together—or, in some cases, against each other. One of the most striking examples comes from her early work with financial executives during the chaos of the 2008 financial crisis. At the time, many leaders treated their bodies like inconvenient vehicles that simply ferried their brains from meeting to meeting. They disregarded sleep, neglected hydration, and barely acknowledged the role their physical health played in their mental performance. The consequences? A rash of heart attacks on the trading floors—not due to high cholesterol or poor diet, but caused by stress alone. It was a wake-up call, not just for the institutions Dr. Swart advised but for the world of neuroscience itself.

The culprit was cortisol. This hormone, which floods your body in response to challenges, is essential for survival in short bursts. But when cortisol levels stay elevated—when the stress doesn’t come down—it begins to wreak havoc. It causes inflammation in the body, disrupts sleep, and leads to fat storage around the abdomen, a vestige of our caveman days when belly fat might have been a life-saving reserve during famine. Dr. Swart jokes that, at one point, financial executives she worked with would simply lift their shirts to show her their “stress belly,” proof of how cortisol had taken up residence in their lives.

Stress is far from a modern problem, though. Dr. Swart explains that much of our biological response to stress was designed for survival in a very different world. Thousands of years ago, human tribes depended on tightly synchronized instincts. Men went on long hunting trips, often traveling far from their original group, while women stayed behind, ensuring the tribe’s survival through communal care. This synchronization extended even to menstrual cycles, a fascinating example of how deeply our bodies are wired to connect and adapt to one another.

But if ancient stress was about survival—outrunning predators, finding food, braving the elements—modern stress feels trickier. It stems from sources like overwork, screen addiction, and loneliness, all of which come with fewer immediate solutions. Dr. Swart argues that what we need now is not just mental resilience but a total realignment with the basics of well-being. The challenge is to convince ourselves—and the people around us—that these basics aren’t just luxuries. They are survival mechanisms.

Take sleep, for instance. Dr. Swart emphasizes its transformative power, not just for your energy levels but for your brain’s health. While we sleep, a little-known system called the glymphatic system cleanses the brain, flushing out toxins like amyloid plaques and tau proteins—the very substances linked to neurodegenerative diseases like Alzheimer’s and Parkinson’s. This deep-cleaning process takes about seven to eight hours, which is why a full night’s sleep isn’t just a luxury—it’s a biological necessity. And if you find yourself waking up during the night, Dr. Swart offers an unexpected tip: turn onto your side. This position helps the brain’s cleaning system work more effectively.

Beyond sleep, Dr. Swart believes in the power of small rituals to calm our overworked brains. Nature, for example, is a balm for the modern soul. Spending time in green spaces doesn’t just reduce stress; it signals to the brain that you’re safe. “If you can spare the mental resources to notice the beauty of a tree or listen to birdsong,” she explains, “your brain knows you’re not just surviving—you’re thriving.”

She also highlights the importance of bonding. Physical touch, eye contact, and even laughter can trigger the release of oxytocin, often called the “bonding hormone.” This chemical not only strengthens relationships but also helps lower stress. Dr. Swart laughs as she describes how something as simple as a heartfelt hug or gazing into someone’s left eye—a connection rooted in mother-infant bonding—can create an emotional resonance that builds trust and intimacy.

Of course, not all stress is bad. Dr. Swart distinguishes between a healthy, adaptive response to challenges—what she calls “good stress”—and the chronic, unrelenting type that corrodes both mind and body. The key is learning to let the peaks of stress return to baseline. If they don’t, your body pays the price. Exercise and journaling, she says, are two effective ways to release pent-up cortisol. Sweating through physical activity literally expels stress hormones, while writing down or speaking aloud what’s on your mind helps clear emotional clutter.

But perhaps the most powerful tool in Dr. Swart’s arsenal is neuroplasticity—the brain’s ability to rewire itself. For decades, scientists believed the brain was static after a certain age, but research has since turned that idea on its head. The brain continues to grow and adapt, even into your sixties and beyond, if you challenge it with new, intense experiences. Learning a language, picking up an instrument, or even taking a new route to work can help reshape the brain, improving not just memory and problem-solving skills but also emotional regulation and creativity.

Ultimately, Dr. Swart’s work reminds us that while stress may be an inevitable part of life, it doesn’t have to define us. Whether it’s by embracing the healing power of nature, prioritizing sleep, or leaning into the connections that bind us, we can all find ways to rewrite our story. After all, our brains are wired not just for survival, but for growth. And in a world full of chaos and cortisol, that might just be the most comforting fact of all.

Articles, podcasts, and videos from Dr. Swart.