How Stress Affects the Body: The Science, Symptoms, and a Functional Medicine Approach
“Don’t let your mind bully your body into believing it must carry the burden of its worries.”
–Astrid Alauda
Stress — and the physical symptoms associated with it — is on the rise. Most Americans report moderate to high stress levels, with 44% stating their stress has increased over the past five years and 77% experiencing physical symptoms caused by stress. It’s estimated that U.S. employers spend over $300 billion annually on healthcare costs and lost productivity linked to stress.
While stress is often brushed off as “just part of life,” chronic stress has real, measurable consequences on nearly every system in the body.
What Is Stress, Really?
Stress is a surprisingly subjective term.
Some people define stress as an unpleasant or distressing circumstance. The American Institute of Stress defines stress as a combination of internal and external factors, both positive and negative, that challenge the body’s ability to maintain balance.
Types of Stress: Acute vs Chronic
Stress can be categorized as:
Acute stress – short-term stress that resolves quickly
Chronic stress – ongoing stress that persists over time
Both can affect health, but chronic stress is where problems tend to accumulate.
Eustress vs Distress
Not all stress is bad.
Eustress is positive, motivating stress that helps you perform, focus, and adapt.
Distress occurs when stress exceeds your body’s ability to recover.
Once stress crosses a certain threshold, it stops being helpful and starts driving symptoms, inflammation, and disease risk.
The Health Impact of Chronic Stress
Research consistently shows that prolonged exposure to stress increases the risk of poor outcomes across many conditions, including:
Asthma
Anxiety and depression
Rheumatoid arthritis
Cardiovascular disease
Chronic pain
Stroke
Cancer
One study found that work-related stress increases the risk of coronary heart disease by 50%. Another showed that women with the highest perceived stress levels experienced biological aging equivalent to at least a decade more than women with low stress. We recommend completing this quick Perceived Stress Scale (PSS) to determine how your stress levels are doing.
Bottom line: chronic stress isn’t just uncomfortable — it’s biologically expensive.
Common Physical and Emotional Symptoms of Stress
Physical Symptoms of Stress
The most commonly reported physical symptoms include:
Fatigue
Headaches
Upset stomach or GI symptoms
Muscle tension
Changes in appetite
Teeth grinding
Dizziness
Changes in libido
Emotional Symptoms of Stress
Emotional symptoms often include:
Irritability or anger
Feeling nervous or on edge
Low energy or burnout
Feeling emotionally fragile or tearful
If any of these feel familiar, your nervous system may be stuck in survival mode.
The Science of Stress: Your Nervous System Explained
The Autonomic Nervous System
Your autonomic nervous system has two main branches:
Sympathetic nervous system (SNS) – “fight or flight”
Parasympathetic nervous system (PNS) – “rest and digest”
Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, triggering the release of cortisol and activating the sympathetic nervous system.
What Happens in Fight-or-Flight Mode?
The sympathetic nervous system is designed to protect you from immediate danger.
When activated, it causes:
Increased cortisol
Elevated heart rate and blood pressure
Increased blood sugar and insulin
Faster breathing
Sweating and heightened alertness
This response is helpful if you’re running from danger — but not if it’s happening all day, every day.
Chronic SNS Activation Can Lead To:
Anxiety and depression
Hypertension and heart disease
Thyroid dysfunction
Sugar and carb cravings
Weight gain (especially abdominal)
If your body believes it’s under constant threat, fat loss becomes nearly impossible. Survival always wins over aesthetics.
Why Modern Life Keeps Us Stressed
These days, most of us aren’t being chased by predators — but our biology doesn’t know that.
We work long hours, juggle demanding jobs, raise families, sleep too little, and often pile on high-intensity exercise in an already stressed state. On a cellular level, the body still perceives danger.
Living in constant fight-or-flight makes it very difficult to heal, recover, or thrive.
The Role of the Parasympathetic Nervous System
This is where the parasympathetic nervous system comes in.
The PNS supports:
Rest and recovery
Digestion and nutrient absorption
Lower heart rate and blood pressure
Hormonal balance
Deep, restorative sleep
Healing happens in this state. Without enough parasympathetic activity, symptoms persist — no matter how “healthy” you’re trying to be.
A Personal Perspective on Stress and Symptoms
In my final year of graduate school, we welcomed our second child. He was an easy baby, slept well, and made life with a newborn manageable alongside full-time school.
On paper, everything looked great.
After graduating, I transitioned into full-time clinical work. Within months, I began experiencing:
Heart palpitations
Chest tightness
Racing heart
Disruptions to my menstrual cycle
My days started early, seeing 15–20 patients, charting, returning calls, managing family life — and then hitting intense HIIT workouts in the evenings. I was postpartum, hormonally vulnerable, and chronically stressed.
Fast forward a year: my symptoms resolved.
With the help of another provider, it became clear that stress was a major driver of my physical symptoms. That experience gave me a deeper understanding of what so many patients feel — and how powerful proper assessment and support can be.
How We Assess Stress at STAT Wellness
At STAT Wellness, we take a functional medicine approach, focusing on root causes rather than symptom suppression.
Because stress affects the body in many ways, we use several tools to assess how your body is coping.
Wellness Panel Testing
For most patients, we start with a comprehensive wellness panel. This evaluates:
Blood quality
Liver and kidney function
Blood sugar and cholesterol
Key nutrients
Hormones like cortisol and DHEA
This test is drawn fasting and within one hour of waking, when cortisol should be at its daily peak. While helpful, it represents only a snapshot in time.
Adrenal Saliva Testing
For patients with suspected adrenal dysfunction, we may recommend a saliva cortisol test.
Collected at home
Four samples throughout the day
Evaluates cortisol and DHEA patterns
Ideally, cortisol is highest in the morning and gradually declines throughout the day, reaching its lowest point at night to support sleep.
DUTCH Hormone Testing
The DUTCH test (Dried Urine Test for Comprehensive Hormones) provides a deeper look at stress physiology.
It measures:
Free and metabolized cortisol
Total cortisol output
DHEA
Estrogen, progesterone, testosterone
Epinephrine and norepinephrine
This test uses multiple samples over 24 hours, offering a comprehensive picture of hormone production, metabolism, and clearance.
Creating a Personalized Plan for Recovery
Using your results, your provider can make targeted recommendations for:
Nutrition
Lifestyle adjustments
Stress regulation strategies
Supplement support when appropriate
The goal isn’t just symptom relief — it’s helping your body feel safe enough to heal.
Because wellness feels good.
If you’re looking for an in depth look at how stress is affecting your health, you can schedule a personalized medical visit with Athena Newell, FNP at STAT Wellness Charleston here!
Sources
https://www.apa.org/monitor/2011/01/stressed-america
https://www.stress.org/daily-life
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5066570/
Kivimäki M, Virtanen M, Elovainio M, Kouvonen A, Väänänen A, Vahtera J. Work stress in the etiology of coronary heart disease—A meta-analysis. Scandinavian Journal of Work, Environment, and Health. 2006;32:431–442. Retrieved from http://dx.doi.org/10.5271/sjweh.1049.
Epel, Elissa S et al. “Accelerated telomere shortening in response to life stress.” Proceedings of the National Academy of Sciences of the United States of America vol. 101,49 (2004): 17312-5. doi:10.1073/pnas.0407162101
Cindy M. de Frias & Erum Whyne (2015) Stress on health-related quality of life in older adults: the protective nature of mindfulness, Aging & Mental Health, 19:3, 201-206, DOI: 10.1080/13607863.2014.924090
https://www.zrtlab.com/diurnal-cortisol-curves-saliva-vs-urine/
