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Cortisol – The Stress Hormone

Tired father taking care baby at home


April is Stress Awareness Month, so let’s learn more about the stress hormone known as cortisol!

While cortisol is known as the stress hormone, it is crucial for the optimal function of your body every day. In healthy individuals, cortisol levels naturally shift throughout the day in a pattern known as a diurnal rhythm. A diurnal rhythm is a circadian rhythm that is repeated every 24 hours and synchronized with the day/night cycle.1 The presence of “stress” or certain medical conditions can affect your cortisol levels and disrupt your healthy diurnal rhythm.2

Here is an example of a healthy diurnal rhythm:

Cortisol Test Adrenal Panel Circadian Rhythm Diurnal Rhythm


We often think of “stress” as the emotional stress we feel when we are stuck in traffic or overwhelmed at work. But, stress encompasses anything that increases the activity of the hypothalamic-pituitary-adrenal (HPA) axis, which controls the release of cortisol.2,3 Pain, prolonged fasting, negative thinking, low blood pressure, acute and chronic infections, low blood oxygen, food sensitivities, intense exercise, low blood sugar, and other circumstances are also interpreted as stress by your body.2

Cortisol directly impacts most organs and cells in your body and the activity of your immune, cardiovascular, respiratory, reproductive, musculoskeletal, integumentary, gastrointestinal, and nervous systems. Therefore, learning more about the stress hormone cortisol and testing your saliva cortisol levels could be the next important step on your path to wellness.3

What is cortisol?

Cortisol is a steroid hormone that is made in your adrenal glands. When stress occurs, the hypothalamus increases the production of corticotrophin-releasing hormone (CRH) to stimulate the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland in your brain. The ACTH then stimulates the release of cortisol from the adrenal glands. The subsequent increase in your cortisol level improves your ability to respond to stressors while maintaining balance or homeostasis, which is why it is known as the stress hormone.2

Stress Response SystemCortisol is produced from cholesterol, the precursor for all steroid hormones, including testosterone and progesterone. To produce cortisol, cholesterol needs to be shuttled into the mitochondria in the cells in the adrenal glands. Once in the mitochondria, the cholesterol is converted to the hormone pregnenolone.4

The pregnenolone is then converted to progesterone, and the progesterone can be converted to 17-OH progesterone, which is pronounced as “17-hydroxy-progesterone.” Finally, enzymes convert the 17-OH progesterone (17OHP) to cortisol in the adrenal glands.4

Here is a picture of the steroid hormone production (steroidogenesis) pathways:



It is possible to have a high cholesterol level (hypercholesterolemia) and a low cortisol level, which could be caused by mitochondrial dysfunction. Researchers have confirmed that mitochondrial dysfunction is associated with hypercholesterolemia, and steroid hormone production occurs in the mitochondria.5 Low levels of other hormones, including testosterone, could also be associated with mitochondrial dysfunction and high cholesterol levels.

Since cholesterol is the precursor for cortisol, low cholesterol levels (less than 150 mg/dL) can also contribute to low cortisol levels.6 Don’t forget to schedule your annual health check-up this year so your doctor can order cholesterol, blood sugar, salivary cortisol, and other important tests.

Stethoscope with calendar page

After cortisol is produced and released by the adrenal glands, it binds to carrier proteins in the blood, such as corticosteroid-binding globulin (CBG) and albumin. Approximately 95% of the circulating cortisol is bound to CBG in the blood, but this percentage can vary. Cortisol must separate, or dissociate, from CBG before it can enter a cell and have an effect.2 This is one reason saliva hormone testing is better than a blood test; saliva offers an opportunity to directly measure the free, bioactive cortisol level.

After the cortisol dissociates from CBG in the blood, it crosses cell membranes throughout the body because the cell membranes are composed of fatty phospholipid bilayers, and cortisol is fat-soluble. When cortisol enters the cell, it binds to a glucocorticoid, or cortisol, receptor. Then, the cortisol-receptor complex enters the nucleus of the cell to affect Gene expression as needed to support the body during times of physical, mental, emotional, and other types of stress.3

Abnormal cortisol levels can be detrimental to your health, whether your cortisol levels are too high, too low, or released in a misaligned diurnal rhythm.3,7

What does cortisol do?

Overall, cortisol helps maintain balance, or homeostasis, in your body during times of stress. Pain, low blood glucose levels, and intense exercise are all types of stress that could induce the release of extra cortisol.2

According to a clinical trial by Goodin et al., increased pain levels directly correlate with increased cortisol levels.8

When pain is experienced, it is usually a cue to get away from the cause of the pain, whether it is a hot stove or a lion attack. If a lion bites you, you need to be able to fight the lion and run away. The stress response and the release of extra cortisol will help you fight, escape, and survive a lion attack (or other causes of pain). The extra cortisol helps maintain homeostasis in your body while you respond to (or escape from) the stressor.

Beautiful Lion Caesar in the golden grass of Masai Mara

The increased cortisol levels seen in the pain study were also associated with lower levels of inflammation, specifically the soluble tumor necrosis factor-alpha receptor II response.8 In general, cortisol and other glucocorticoids are considered anti-inflammatory, but because life is often complicated, the effects of cortisol on the immune system are not black & white.9

Cortisol can also induce inflammatory effects at times. Research shows the initial low levels of cortisol during a stress response have an inflammatory effect, while the higher levels of cortisol that are associated with a more prolonged stress response are anti-inflammatory.9

With regard to homeostasis or balance, scientists hypothesize that the anti-inflammatory effects of higher cortisol levels help prevent excessive destruction from the initially elevated levels of inflammation present during a stress response or trauma. The anti-inflammatory activity of higher cortisol levels also appears to prevent the development of autoimmune diseases.9

Glucocorticoids, including cortisol, can induce the cell death of pro-inflammatory T cells, suppress B cell antibody production, reduce neutrophil migration, and affect the immune system in other ways to reduce inflammation.3,8

Cortisol hormone increased or decreased level symptom scheme outline

Cortisol also increases the amount of glucose and other energy sources present in the blood as part of the stress response.2 Since the brain prefers glucose as an energy source, the more glucose available to the brain during a stressful event, such as a lion attack, the better!10 In the liver, cortisol increases a process called gluconeogenesis, which is the production of glucose. Cortisol also enhances the activity of other hormones that increase the blood glucose level, including glucagon, epinephrine, and other catecholamines.3 This is how the release of extra cortisol helps re-balance a low blood glucose level and how the stress response provides the energy needed to respond to a stressful situation.

Cortisol stimulates muscle cells to increase protein degradation, increasing the level of amino acid building blocks available in the blood so the liver can increase glucose production. Yes, your liver can produce sugar from amino acids! In fat (adipose) tissue, cortisol increases lipolysis, or the breakdown of fat, to provide another source of immediate energy for your body.3

Hormone cortisol and human organs

Cortisol has many valuable effects on the body during intense exercise, which is a beneficial stress. As discussed above, cortisol increases the availability of metabolic nutrients, including fatty acids, amino acids, and glucose, for the energy needs of muscles and other tissues during exercise.3,11

Cortisol helps maintain normal blood vessel integrity and responsiveness during exercise. Cortisol also prevents an overreaction of the immune system to repeated exercise-induced muscle damage and reduces inflammation to hasten recovery. And, even though exercise is a stress on the body, it is beneficial stress because, over time, regular physical exercise leads to less stress reactivity and enhanced stress recovery from emotional stress and other types of stress, compared to untrained subjects.11

Underlying Causes and Symptoms of Abnormal Cortisol Levels

While the stress response, including the release of extra cortisol, is beneficial and helps you respond to and re-balance during stress, an abnormal cortisol level due to too much long-term stress, an underlying medical condition, or other cause can be harmful.

High cortisol levels can be caused by Cushing syndrome, an acute stress response, the early stages of chronic stress, major depressive disorder (MDD), and other conditions.12,13

Chronically elevated cortisol levels are associated with many concerning health issues, including weight gain and obesity; muscle loss; high blood sugar levels and diabetes; insulin resistance; chronic infections; high blood pressure; increased risk of developing cardiovascular disease; loss of bone mineral density; memory loss; insomnia and other sleep issues; fragile or thinning skin; mood disorders, including anxiety and bipolar disorder; and abnormal cholesterol levels.12,14

Low cortisol levels can also be harmful.

A low cortisol level could be caused by Addison’s disease; congenital adrenal hyperplasia (CAH); Post-traumatic Stress Disorder (PTSD); long-term chronic stress or adrenal fatigue; long COVID and other chronic infections; mitochondrial dysfunction; current or past history of prescription corticosteroid medication(s); low cholesterol levels due to malabsorption syndromes, the use of statin medications, liver dysfunction, or other causes; and other medical conditions.13,15-22

Chronically low cortisol levels (hypocortisolism) can be an underlying cause of or contributing factor to many health concerns, including chronic fatigue syndrome (CFS), low blood pressure (hypotension), hypoglycemia (low blood sugar levels), weight loss, burnout with physical symptoms, asthma, rheumatoid arthritis, flexion contracture, fibromyalgia, and other chronic pain syndromes.23-26

Even if the total amount of cortisol released by the adrenal glands in 24 hours is normal, an abnormal diurnal rhythm is associated with suboptimal health. Ideally, your cortisol level should be at its highest just after awakening in the morning and lowest at night before bedtime. Some have high cortisol levels at night and low cortisol levels in the morning. This abnormal rhythm, or a circadian misalignment, is associated with daytime fatigue, insomnia, obesity, and many other health concerns.7,27

Mom freelancer trying to concentrate on distant remote work while small daughter disturbing her

If you have any of the symptoms or health conditions mentioned above, such as fatigue, insomnia, long COVID, anxiety, high cholesterol, depression, or high blood pressure, consider asking your doctor to order a cortisol saliva test to assess the health of your adrenal glands and diurnal rhythm soon!

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.



If you could choose, would you rather spit into a tube or have a needle jabbed into your arm to measure your hormone levels? We suspect you would rather not get stuck with a needle, and you do have a choice! Saliva hormone testing offers many benefits, including painless collection in the comfort of your home at any time. Saliva hormone tests can help determine the underlying cause(s) of PMS, insomnia, anxiety, fatigue, infertility, migraines, weight gain, hot flashes, hair loss, and many other health concerns.


Do you enjoy watching college basketball games during March Madness every year? We do! Around here during March, we also like to focus on the importance of healthy magnesium supplements, which we call Magnesium Madness! Our first March blog post highlighted the beneficial effects of magnesium on insulin resistance, and the Magnesium Madness continues with our second blog post on magnesium and healthy blood pressure.


March is here, which means many spring delights, including warmer weather, March Madness, gardening, baseball, and spring break, are just around the corner. Here at InterPlexus, we are dedicating our March blog posts to magnesium – a truly powerful and magical mineral that is rarely consumed in adequate amounts. Magnesium (Mg) is required for the regulation of many functions in your body because it is a cofactor or activator in hundreds of enzymatic reactions.


Chronic stress is a frequent underlying cause of low nutrient levels and health issues. In fact, according to the World Health Organization (WHO), approximately 450 million people worldwide are affected by stress-related disorders. Research indicates stress could be responsible for an estimated 70% of visits to primary care providers, which is shocking. Fortunately, the consistent use of a synergistic blend of vitamins, minerals, and herbal extracts that nourish the adrenal glands could support a healthy stress response.*


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