Stress Is Silently Sabotaging Your Health. Here’s How a Cortisol Test Can Help

February 1, 2024

Did you know that a cortisol test could save your life? Your body relies on several chemical messengers to keep coordinated. One of them is cortisol, which is in charge – among many things – of kickstarting your body’s reaction when you encounter a stressful situation.

We will explore the role of cortisol in your body, but first, let’s see how a test exposes invisible dangers.

Saved By a Cortisol Test

As Harvard’s book, Age of Scientific Wellness, illustrates, a cortisol test might save your life. The book shares the story of a 33-year-old woman who decided to understand why she felt stressed out despite not facing traumatic life events typically associated with psychological stress.1 Her cortisol test results showed out-of-the-ordinary elevated numbers; nevertheless, these results didn’t point to a specific condition.

However, the test functioned as an early warning system that led her to undergo further testing, revealing stage III colon cancer that was addressed on time and saved her life.

Impressive, right? The story illustrates the power of preventive testing, which you can harness today.

Testing 2.0

Kyla, the leader app in anti-aging programs, believes that the best time to rely on diagnostic tests is when you feel fine. Why? When you rely on a tool like a cortisol test as a preventive resource, you can stop a disease before it takes hold. 

As Nature reports, AI models – like Kyla’s risk engine – that combine cortisol testing with other diagnostic tools showed a 96% accuracy in flagging patients at higher risk of long COVID-19.2

The transformative power of preventative testing comes at a time when American stress levels are dangerously high.

America Under (Stress) Attack

According to the American Psychology Association, 27% of Americans say they are so stressed they can’t function most days. Curiously, 67% of Americans minimize the importance of their stress by saying that they know other people have much bigger problems, which explains why 40% don’t seek help, as they believe stress reduction techniques don’t work.3

This is a big misconception that we must address.

Stress Is Not Inevitable

Our times are characterized by stress. However, looking back at human history, finding a specific period in which life was simple is challenging. Stress is a part of the human experience.

So, how do you live in harmony with stress? You manage it. Breathing exercises, yoga, meditation, and other interventions are highly effective and easy to incorporate into your life.  

And tools like a cortisol test can remind you it’s time to take a deep breath and regulate your stress levels.

You Can Strengthen Your Heart

A Circulation study found that individuals with heart problems who took part in a stress management program increased their survival rates, and incidents of heart attacks and strokes significantly dropped.4

Controlling The Silent Killer

JAMA Network found that people with high blood pressure saw significant reductions – 6.1 mm Hg systolic drop – after personalized stress management sessions.5

Lowering Stress (and Blood Sugar)

Diabetes Care found that a stress management intervention, independent from diet and exercise regimes, significantly reduced HbA1c levels – a key blood sugar marker – in diabetes patients.6

Okay, managing your stress is possible, but why is stress so damaging, and what’s cortisol’s role?

Stress and Your Body

Cortisol is a hormone – produced by the adrenal glands – that helps communication between cells in different organs, coordinating their activities, as The Oxford Textbook of Medicine explains.7

Cortisol is critical in how your body reacts to stress. Physical stress – like illness – or psychological stress – such as fear – puts your body on alert. Cortisol rises when you perceive a threat, activating the “flight or fight” response, a mechanism that helps your body react quickly to an immediate danger, as Physiological Reports declares.8

As stress is no picnic, you might get mad at cortisol, so it’s time to address three common misunderstandings.

Cortisol and Stress Misunderstandings

1) Cortisol Is Not Your Enemy

You will find only negative videos if you search “cortisol” on YouTube. Cortisol rises when you are stressed, so cortisol is a villain that must be defeated. Not so fast.

Cortisol is not the bad guy. As the National Institutes of Health (NIH) and Chronic Stress Journal warn, you wouldn’t be alive without it.9-10 Cortisol:

  • Boosts glucose: Fuels your brain under stress, ensuring sharp thinking.
  • Fine-tunes immunity: Prevents overreaction, protecting against inflammation.
  • Accelerates heart and breath: Keeps you energized and ready for action.
  • Balances metabolism: Manages energy reserves, avoiding burnout.
  • Energizes cells: Supports muscle and organ function for peak performance.

2) You Don’t Need to Reduce Your Cortisol Levels at All Costs

According to social media, too much cortisol causes insomnia, bad moods on Mondays, and relationship troubles. But according to science, reality is more complex. If your body’s cortisol secretion, whether high or low, shifts very little in response to your day-to-day environment, you might be in trouble. 

A study in Psychoneuroendocrinology revealed that a natural cortisol cycle – a normal range peaking in the morning to wake you and dipping by bedtime to help you sleep – halved the risk of heart-related deaths and reduced stroke risk by 29%. Conversely, individuals with high cortisol levels at night, showing a disrupted daily cortisol rhythm, faced a 49% increase in heart-related death risk and a 24% higher chance of stroke.11

So, it’s not whether your cortisol levels are high or not. It’s when they’re elevated. A cortisol test will help you clarify if your cortisol fluctuations are in rhythm with your body’s needs.

3) “Minor” and ”Big” Problems Equally Cause Stress

Stress does not require big problems to manifest. Research by the Journal of Behavioral Medicine found that a significant cause of stress is “daily hassles.'” From a logical perspective, a traffic jam when you’re already late shouldn’t affect your well-being. However, minor stressors pile up in daily life, becoming a major cause of stress.12

If you’re a worrier (we all are at times), as The American Psychological Association explains, by thinking about (apparently) minor nuisances, you pump cortisol, prolonging the time you consider a stressful event stressful.13

Now that you understand that it’s okay to be stressed about seemingly innocent inconveniences, it’s time to know why stress – no matter the cause – is dangerous.

Negative Effects of Stress

Stroke Risk

The Stroke Association and the Journal of Neurological Sciences explain that elevated cortisol levels can increase factors that elevate the risk of stroke, such as blood cholesterol, blood sugar, hypertension, and triglycerides.14,15

Emotions and Heart Problems

Research by the British Heart Foundation recognizes the influence of emotional stress on heart disease development. Elevated cortisol levels can cause unwanted inflammation – as cortisol regulates it – so excessive levels can make cells more sensitive, potentially damaging your heart and blood vessels.16

Metabolic Imbalances

Nature Reports comments that high cortisol levels contribute to obesity by changing your fatty tissues, creating inflammation, and leading to insulin resistance.17

Experimental and Clinical Endocrinology & Diabetes journal has found that people with diabetes have an imbalanced cortisol cycle, with lower morning levels and high evening cortisol.18

If cortisol is called the “stress hormone,” why is it involved in so many issues? Great question.

Everything in Your Body Is Connected

Cortisol by itself is not the only marker of stress. Cortisol is just the middleman delivering messages across your body so that every experience and environmental situation is processed in a balanced way.

Your body is constantly pushing for a state of balance. That state is only possible if all the systems are working together as a whole.

When you’re stressed, elevated cortisol is just a marker of dysregulation. Not the root cause. So, how can you find an imbalance’s underlying causes?

By relying on a tool – like the Kyla app – that shows every potential health risk you face.

Finding The (Real) Reasons Why Your Cortisol Is Elevated

Cortisol levels, according to the New England Journal of Medicine, can be disrupted due to lifestyle factors, such as shift work and irregular sleep patterns.19

So, what initially appears to be a cortisol problem reveals its true face: a body problem. Your body is a team player. What happens in one place affects the whole.

Cortisol imbalanced symptoms, as Cedars-Sinai cautions, can be vague and potentially reflect other conditions, such as depression and chronic fatigue, making testing essential for correct diagnosis and interventions.20

That’s why Kyla uses a cortisol test as one of many diagnostic tools.

A Cortisol Test Supercharged by Kyla’s Risk Engine

According to the NIH, a cortisol blood test or a saliva test is a reliable marker for calculating the levels circulating in your body. Nevertheless, as you have seen, cortisol is an active member of your body’s communication network.9

So, how can you translate what your cortisol test results are saying to you? With your body’s interpreter: Kyla.

Let’s look at some studies that show how AI-driven insights can change care delivery as we know it.

Unmasking Invisible Metabolic Threats: Genetically-driven elevated cortisol levels, as Clinical Endocrinology Journals explains, are associated with hypertension and obesity. Kyla – by incorporating these unique risk factors – can reveal if a person’s overweight is caused by unexpected reasons easily missed by traditional tests, such as abnormal cortisol levels.21

Physician Burnout Detector: Almost 50% of American physicians manifest burnout symptoms, according to PLOS One, which increases the risk of medical errors. An AI model – such as Kyla – analyzing cortisol levels with other tests detected with a 76% accuracy, which medical professionals presented elevated stress levels.22

Kyla: The Future of Personalized Testing

Kyla, analyzing a small blood sample can save your life. Our mission is to make the best diagnostic solutions available in a convenient app that leverages proprietary AI technology that identifies hidden risks other tests miss.

By analyzing what makes you unique – your genetic inheritance, lifestyle habits, and health status – we multiply the diagnostic power of a cortisol test so you can identify the underlying cause of any imbalance and act when it matters: before you get sick.

Download the Kyla App to access an anti-aging blueprint – at your fingertips – that will propel your well-being to where it deserves to be.


  1. Hood L, Price N. Age of scientific wellness: Why the future of medicine is personalized, predictive, data-rich, and in your hands. Cambridge: Harvard University Press; 2023.
  2. Klein J, Wood J, Jaycox JR, Dhodapkar RM, Lu P, Gehlhausen JR, Tabachnikova A, Greene K, Tabacof L, Malik AA, Silva Monteiro V. Distinguishing features of Long COVID identified through immune profiling. Nature. 2023 Nov 2;623(7985):139-48.
  3. American Psychological Association. Stress in America 2023: A Nation Graffing with Psychological Impacts of Collective Trauma. American Psychological Association; [cited 2024 Jan 29]. Available from:
  4. Blumenthal JA, Sherwood A, Smith PJ, Watkins L, Mabe S, Kraus WE, Ingle K, Miller P, Hinderliter A. Enhancing cardiac rehabilitation with stress management training: a randomized, clinical efficacy trial. Circulation. 2016 Apr 5;133(14):1341-50.
  5. Linden W, Lenz JW, Con AH. Individualized stress management for primary hypertension: a randomized trial. Archives of Internal Medicine. 2001 Apr 23;161(8):1071-80.
  6. Surwit RS, Van Tilburg MA, Zucker N, McCaskill CC, Parekh P, Feinglos MN, Edwards CL, Williams P, Lane JD. Stress management improves long-term glycemic control in type 2 diabetes. Diabetes care. 2002 Jan 1;25(1):30-4.
  7. Firth JD, Conlon C, Cox TM. Oxford Textbook of Medicine. Oxford: Oxford University Press; 2020.
  8. Jones C, Gwenin C. Cortisol level dysregulation and its prevalence—Is it nature’s alarm clock?. Physiological reports. 2021 Jan;8(24):e14644.
  9. Thau L, Gandhi J, Sharma S. Physiology, Cortisol. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from:
  10. McEwen BS. What is the confusion with cortisol?. Chronic Stress. 2019 Jan;3:2470547019833647.
  11. Karl S, Johar H, Ladwig KH, Peters A, Lederbogen F. Dysregulated diurnal cortisol patterns are associated with cardiovascular mortality: Findings from the KORA-F3 study. Psychoneuroendocrinology. 2022 Jul 1;141:105753.
  12. Kanner AD, Coyne JC, Schaefer C, Lazarus RS. Comparison of two modes of stress measurement: Daily hassles and uplifts versus major life events. Journal of behavioral medicine. 1981 Mar;4:1-39.
  13. Verkuil B, Brosschot JF, Gebhardt WA, Thayer JF. When worries make you sick: A review of perseverative cognition, the default stress response and somatic health. Journal of Experimental Psychopathology. 2010 Nov;1(1):jep-009110.
  14. Stroke Association. Stroke statistics [Internet]. [cited 2024 Jan 29]. Available from:
  15. Slowik A, Turaj W, Pankiewicz J, Dziedzic T, Szermer P, Szczudlik A. Hypercortisolemia in acute stroke is related to the inflammatory response. Journal of the neurological sciences. 2002 Apr 15;196(1-2):27-32.
  16. British Heart Foundation. How does psychological stress affect your heart and blood vessels? British Heart Foundation; 2021 [cited 2024 Jan 29]. Available from:
  17. Hotamisligil GS. Inflammation and metabolic disorders. Nature. 2006 Dec 14;444(7121):860-7.
  18. Lederbogen F, Hummel J, Fademrecht C, Krumm B, Kühner C, Deuschle M, Ladwig KH, Meisinger C, Wichmann HE, Lutz H, Breivogel B. Flattened circadian cortisol rhythm in type 2 diabetes. Experimental and clinical endocrinology & diabetes. 2011 Apr 6:573-5.
  19. McEwen BS. Protective and damaging effects of stress mediators. New England journal of medicine. 1998 Jan 15;338(3):171-9.
  20. Cedars Sinai. Is adrenal fatigue a medical myth? [cited 2024 Jan 29]. Available from:
  21. Lee WH, Larsson SC, Wood A, Di Angelantonio E, Butterworth AS, Burgess S, Allara E. Genetically predicted plasma cortisol and common chronic diseases: A Mendelian randomization study. Clinical Endocrinology. 2023 Sep 5.
  22. Xu S, Arnetz JE, Arnetz BB. Applying machine learning to explore the association between biological stress and near misses in emergency medicine residents. Plos one. 2022 Mar 8;17(3):e0264957.