We all know what the stress in physical terms – although symptoms vary from person to person. Some people experience tremors or palpitations, others develop muscle tension, headaches or stomach pains. But what we don’t always realize is that our physiological responses to the stresses and strains of life can have deeper and less obvious repercussions on virtually every organ and system in the body.
“I think people really underestimate the size of the effects,” said Janice Kiecolt-Glaser, director of the Behavioral Medicine Research Institute at the Ohio State University School of Medicine. When you’re under stress, your brain triggers the release of a cascade of hormones — such as cortisol, epinephrine (also known as adrenaline), and norepinephrine — that produce physiological changes. These changes, called the stress response or fight-or-flight response, are designed to help people react to or deal with the threat or danger they are facing.
The problem is that these changes can and do occur in response to non-life-threatening stressors—situations like work deadlines, traffic jams, financial pressures, and family conflicts—and, over time, can affect the body and mind. “People understand the big stressors, but they don’t pay attention to the smaller stressors that build up and also make a difference,” said Kiecolt-Glaser.
What follows is a detailed look at how stress can affect various organs and systems in the body, from head to toe.
Acute forms of stress — when you’re facing a work deadline or arguing with a loved one, for example — can actually be beneficial in the short term, bathing the brain with hormones (like cortisol) that help improve your motivation and ability. of focus and performance, according to Wendy Suzuki, a professor of neuroscience and psychology at New York University and author of Good Anxiety: Harnessing the Power of the Most Misunderstood Emotion.
On the other hand, the prolonged elevated cortisol levels that accompany chronic stress and post-traumatic stress disorder (PTSD) can interfere with and damage the brain’s hippocampus, which is critical for long-term memory function, Suzuki said. . In the long term, increases in cortisol can also damage the brain’s prefrontal cortex, which is essential for focused attention and executive function (cognitive processes that allow you to plan, organize, solve problems, engage in flexible thinking and control). their impulses).
With acute stress, your heart rate speeds up and your blood pressure rises so that (evolutionarily speaking) you can prepare to fight or flee for your life. After the stressful encounter passes, these functions should return to their normal states. But this is not always the case in the modern world, where we often find only stressors after stressors.
Chronic stress, which occurs over months to years, can lead to high blood pressure, adiposity (accumulation of fat), insulin resistance and increased systemic inflammation, explained Ahmed Tawakol, co-director of the Center for Cardiovascular Research and director of nuclear cardiology at the Massachusetts General Hospital and Harvard Medical School. “Together, they drive the buildup of arterial plaque and increase the risk of heart attack and stroke.”
Over time, stress can also lead to narrowing of blood vessels and increased blood clotting, which further increases the risk of heart events. It’s also possible that when someone faces an acute stressor in addition to chronic stress, it “has an additive effect such that acute stress can trigger a heart attack or stroke,” Tawakol said.
During a stressful situation, the sympathetic nervous system speeds up and stress hormones are released, which leads to rapid breathing and can make you find it difficult to catch your breath. This can affect the transport of oxygen and carbon dioxide in the blood. “Rapid, shallow breathing is not a good thing – you’re not getting rid of carbon dioxide optimally and you can starve yourself of oxygen, which can lead to symptoms like dizziness and vertigo,” noted Neil Schachter, a lung specialist. and professor of medicine at Mount Sinai Medical Center in New York.
Both acute and chronic stress can trigger asthma attacks or exacerbate chronic obstructive pulmonary disease (COPD) in people who have these conditions. A review of studies in a 2017 issue of the journal Respiratory Medicine found that active stressors (like having to complete a math task) and passive stressors (like watching stressful movies) led to increases in sympathetic nervous system activation, and the passive form of stress was also associated with mild bronchoconstriction among people with asthma .
During a stressful event or period of time, stress hormones such as cortisol travel to the immune system and have various disruptive effects. One is by triggering heightened inflammation, which is at the root of many conditions, including cardiovascular disease and dementia, noted Kiecolt-Glaser. “When you’re under stress, you can have a release of pro-inflammatory cytokines,” proteins that affect immune function.
While short-term inflammation usually helps the body heal — think of the swelling that develops around a sprained ankle, increasing blood flow to the area — excessive or chronic inflammation can turn against healthy cells, making them more vulnerable to infections, less responsive to vaccines and slower to heal.
Furthermore, the release of pro-inflammatory cytokines can travel to the brain and increase the risk of depression. When it comes to stress and depression, “it’s an unpleasant cycle,” said Kiecolt-Glaser. “When you are depressed, you end up sleeping poorly and being less likely to exercise, which can increase inflammation and depression.”
Stress decreases gastrointestinal motility (slowing down of bowel emptying), which can make you feel sick, bloated or constipated, explained gastroenterologist Cindy Yoshida, a professor of medicine at the University of Virginia Health System in Charlottesville. But the main news is: stress causes changes in the gut microbiome, impairing bacterial diversity, which affects gut barrier function in ways that increase gut permeability. This means that bacterial byproducts from the food you eat can leak from your intestinal tract into your circulation, which in turn triggers inflammatory and hormonal responses, Yoshida explained.
Among other effects, these changes can exacerbate irritable bowel syndrome and inflammatory bowel disease (IBD). In fact, a study in a 2020 edition of PLOS One found that psychological stress was related to flare-ups of Crohn’s disease and ulcerative colitis among 1,078 people with IBD — and 75% of participants were aware of this effect. To make matters worse, “there’s enough communication between the gut and what’s going on in the brain: stress can increase gut permeability, and gut permeability can also cause anxiety and depression,” Yoshida said.
If you’ve ever had a flare-up of acne or eczema when you were stressed, you’re well aware of the effects of stress on the skin, which is the largest organ in the human body. “We used to think of the skin as a wrapper, keeping our insides in and the rest out,” according to Rick Fried, a dermatologist and clinical psychologist and clinical director of Yardley Dermatology Associates and the Yardley Research Clinic in Yardley, Pennsylvania. . “Over the years, we’ve come to realize that the skin is a very active organ in its own right – it has its own immune system and it’s interacting with the brain at every moment.”
As a result, when you experience acute or chronic stress, the skin’s immune system is activated, which promotes inflammation, leading to a worsening of skin conditions such as rosacea, psoriasis, hives, and eczema.
Stress can also interfere with the skin’s ability to retain water — and the cascade of stress hormones that are released causes the skin’s sebaceous glands to produce more oil, which can trigger acne, said Joshua Zeichner, an associate professor of dermatology at the Hospital. Mount Sinai in New York.
“A few days after a stressful event, we see the effects on the skin. The impact of stress on the skin is real.” And to make matters worse, it can lead to a vicious cycle where stress can cause a skin condition that, in turn, creates more distress and exacerbates or prolongs the skin condition, Fried added.
What to do
Understanding how stress affects the body can help you realize the importance of mitigating it. And for the most part, the harmful effects of stress are somewhat variable, experts said.
If you exercise regularly, get good quality sleep, and take steps to reduce and/or manage your stress, “you can reduce brain stress activity, systemic inflammation, and your risk of developing cardiovascular disease,” Tawakol said.
You can also decrease your stress reactivity by doing deep breathing exercises, progressive muscle relaxation, meditation, yoga, or aerobic exercise, which will help calm your body’s stress response, Fried advised.
Adopting these strategies is a good idea, as stressful events and situations – big and small – aren’t going to go away anytime soon.
Remember: “It’s not just the big stressors that matter — the smaller stressors that build up matter too,” said Kiecolt-Glaser, “especially if you don’t manage them.”
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Stacey Colino is a writer in Chevy Chase, Maryland, specializing in health and psychology and co-author of Emotional Inflammation: Discover Your Triggers and Reclaim Your Equilibrium During Anxious Times.
TRANSLATION BY RENATO PRELORENTZOU