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Cortisol Hormone: Its Role In Stress, Inflammation, And Weight Gain


Cortisol is your body’s main stress hormone. Your lifestyle and stress levels affect the daily rhythms of cortisol in your body.

If you’re stressed out day-to-day and spend a lot of time in a fight-or-flight state, you probably have high cortisol levels.

Your health habits, diet, environment, and even your thoughts influence your cortisol levels. Too much or too little cortisol can have a negative impact on your blood pressure, blood sugar levels, immune system, sleep, mood, memory, and more.

The good news is that there are natural, safe, easy ways to reduce high levels of cortisol and rebalance the production of cortisol in your body. This article will cover how cortisol works, and how you can manage stress to keep your cortisol levels healthy and perform your best.

What Is Cortisol?

Cortisol is a hormone produced and released by your adrenal glands, little triangle-shaped glands that sit on top of your kidneys.

Cortisol is one of your body’s “fight-or-flight” hormones (adrenaline is the other). When you experience a stressful or frightening situation, your adrenal glands start pumping out cortisol, preparing your body to take immediate action.

Cortisol pumps glucose into your bloodstream for fuel, increases heart rate and blood pressure, and shuts off digestive and reproductive function so you have more energy to dedicate to surviving whatever stressor is threatening you.

Outside of the short-term stress response, cortisol also regulates your body’s daily functions. It helps control your blood pressure and heart rate to keep you in homeostasis (a state of healthy balance).

Cortisol also helps to control your sleep-wake cycle. It increases in the morning, waking your body up and making you alert enough to start your day.

In conjunction with the hormone insulin, cortisol also regulates the way you break down carbohydrates, proteins, and fats according to your body’s energy intake and needs.

Other factors that influence cortisol levels include natural and manmade light exposure, the season, day length, the timing of meals, and being in urban or natural environments.

How Does Cortisol Work?

Cortisol levels rise and fall in your body throughout the day.

If you’re healthy, cortisol is highest in the morning[*]. It helps wake you up and prepares you to face the day with the cortisol awakening response, a dramatic rise in early morning cortisol levels.

Your body controls cortisol release through the hypothalamic-pituitary-adrenal (HPA) axis, a feedback system involving your hypothalamus (a part of your brain) and your pituitary gland. This feedback loop adjusts your cortisol levels up or down depending on the time of day.

Outside of normal daily fluctuation, cortisol also turns on in response to stress.  Emotions like fear, disgust, and anger trigger immediate cortisol release.

You also release cortisol when you feel threatened, whether the threat is real (a snake in front of you) or hypothetical (thinking you’ll be fired from your job).

Once released, cortisol does its job by binding to the glucocorticoid receptor, a nuclear receptor found in most cells throughout your body.

Receptors are complex proteins that act like a switch or a lock-and-key system to allow your cells to respond to specialized hormones like cortisol.

Once a cortisol receptor is activated by the presence of cortisol, it changes the behavior of a cell.

The role of cortisol varies depending on the type of cell it interacts with. Because cortisol can influence most cell types, it plays many different roles depending on the situation and type of cell.

The Many Roles of Cortisol

Here are some of the essential roles cortisol plays at the cellular level:

  • Releasing glucose (sugar) in “fight-or-flight” scenarios, so you have more energy to deal with immediate threats
  • Controlling your immune function
  • Limiting short-term inflammation through anti-inflammatory mechanisms (after you work out, for example)
  • Setting your sleep-wake cycle
  • Counteracting melatonin, a hormone that makes you sleepy, to help you wake up in the morning or stay awake during an emergency

Cortisol affects your metabolism, weight, immune function, inflammation, sleep quality, and more. It’s important to keep it balanced.

Chronic Stress and Cortisol

Unfortunately, if you live a fast-paced modern lifestyle without proper stress management, your body can stay in more-or-less constant fight-or-flight mode.

Chronic stress throws off your cortisol rhythm, resulting in either high or low cortisol levels.

And both can wreak havoc on your blood sugar, cause high blood pressure, compromise immune function, disrupt sleep, and impact other vital aspects of your health — including mental health.

High chronic stress levels have also been linked in studies to cortisol dysregulation.

Dysregulation means your daily cortisol rhythms are broken: instead of a high spike in the morning, you may have a flat curve, or a cortisol spike at inappropriate times (such as higher nighttime cortisol levels leading to insomnia).

Cortisol dysregulation from chronic stress is associated with higher risk of type 2 diabetes, depression, high blood pressure, and other health problems[*].

Another type of dysregulation occurs when your cortisol feedback loop becomes compromised, allowing cortisol levels to rise inappropriately and stay elevated well after you experience stress. Cortisol feedback loop degradation is associated with chronic pain problems, as well as anxiety[*].

What Happens If You Have Too Much Cortisol

Hypercortisolism is the medical name for very high levels of cortisol. The long-term effects of hypercortisolism are known as Cushing syndrome.

Cushing Syndrome

Cushing syndrome occurs when your body is exposed to too much cortisol over a long period of time.

Signs of Cushing syndrome include:

  • Rapid weight gain
  • Pink or purple stretch marks on the midsection, upper legs, breasts, and arms
  • Thin, fragile skin
  • Slow healing and bruising easily
  • Irregular or absent periods in women
  • Body and facial hair growth (hirsutism) in women
  • Decreased libido, infertility, and erectile dysfunction in men

The signs and symptoms of Cushing’s syndrome are difficult to overlook.

Causes of Cushing syndrome include:

  • Some medications
  • A tumor in the pituitary gland
  • An ectopic tumor
  • An adrenal tumor
  • Heritable genetic traits

Most tumors that cause overproduction of cortisol are not cancerous.

If you suspect you may have Cushing syndrome, speak to a trusted physician about treatment. Many Cushing patients experience relief or reversal of symptoms with proper diagnosis and treatment.

If you don’t have Cushing syndrome, you may still have excessive levels of cortisol. This is called subclinical hypercortisolism.

Subclinical Hypercortisolism

If you suffer from subclinical hypercortisolism, your high cortisol levels may not be so obvious to a doctor, but can still cause problems as long as they go undetected.

The most common cause of high cortisol levels is chronic stress. That’s why stress is a major problem in modern life.

Stress and high cortisol are implicated in a lot of chronic health conditions. All of the following issues can be caused or worsened by excessive stress and elevated cortisol levels:

elevated cortisol levels

Chronic high cortisol is also linked to depression and Alzheimer’s dementia[*].

When cortisol is high all the time, your body has trouble entering a relaxed and restful state. If you feel like you’re stuck in fight-or-flight mode and can’t wind down, your cortisol levels may be high.

Pregnenolone steal is another way that high cortisol can cause issues — and this one affects other important sex hormones.

Pregnenolone Steal

Your adrenal glands produce cortisol from a prohormone called pregnenolone, which comes from cholesterol.

Prohormones are precursors to other hormones, and pregnenolone is the raw ingredient for all steroid hormones in your body (male and female sex hormones, as well as adrenal hormones).

When your body makes a lot of cortisol, your pregnenolone levels can become depleted. Your body may not have enough pregnenolone available to produce other steroid hormones, which can lead to deficiencies and imbalances of other hormones, like testosterone and estrogen.

Managing stress and balancing your cortisol levels are effective ways to deal with pregnenolone steal.

What Happens If You Have Too Little Cortisol

When your body doesn’t produce enough cortisol, you suffer from hypocortisolism or very low cortisol. Hypocortisolism is also called Addison’s disease or adrenal insufficiency.

Addison’s Disease

Addison’s disease usually develops over several months. Here are the telltale signs and symptoms:

  • Severe fatigue
  • Decreased appetite
  • Weight loss
  • Skin-darkening (hyperpigmentation)
  • Low blood pressure, sometimes leading to fainting
  • Low blood sugar
  • Craving salt
  • Pain in your abdomen, muscles, or joints
  • Depression, irritability, and other mood issues
  • Loss of body hair or sexual function in women

Common causes of Addison’s disease include[*]:

  • Traumatic brain injury (TBI) that affects your HPA axis
  • An infection affecting your adrenal glands
  • Cancer spreading to the adrenal glands

Like Cushing syndrome, Addison’s disease is hard to ignore. Doctors usually treat adrenal insufficiency with steroids like prednisone or hydrocortisone.

Low Cortisol Levels

If you don’t have Addison’s, you may still have low cortisol without meeting the criteria for clinical hypocortisolism. These are the typical symptoms of low cortisol:

  • Fatigue
  • Dizziness
  • Weight loss
  • Lack of appetite
  • Nausea, diarrhea, and other gastrointestinal issues

Long-term low cortisol is also linked to joint pain and inflammation from rheumatoid arthritis[*].

Some people suffer from low cortisol after years of living with chronic high stress levels.

Excessive stress all the time elevates cortisol, but as time passes your body may learn to ignore the stress signals from your hypothalamus and pituitary gland.

If you become insensitive or resistant to corticotropin-releasing hormone (CRH) or adrenocorticotropic hormone (ACTH), the adrenal cortex at the top of each kidney won’t release enough cortisol, even when your body urgently needs it.

Cortisol Dysregulation

Cortisol dysregulation is when you release cortisol at the wrong times throughout the day. Even if your cortisol levels over 24 hours are acceptable or “normal” on average, your daily rhythm of cortisol can still be out of balance

Unlike Cushing syndrome and Addison disease, cortisol dysregulation is often difficult to perceive and detect. It’s also a lot more common than hypercortisolism or hypocortisolism.

When your body is working the way it should, your cortisol blood levels are highest in the morning, about 30 minutes after you wake up, then drop during the day.

They reach their lowest levels between 6 pm and 12 am, allowing you to relax and go to bed, then they begin slowly climbing at night and peak again the next morning.


Normal Cortisol Rhythm [*]

Cortisol dysregulation takes several forms:

  • Low morning cortisol levels
  • High evening or nighttime cortisol levels
  • “Rigid” patterns (shallow or flattened curve[*])
  • Impaired stress response
  • Exaggerated or prolonged stress response

Low morning cortisol levels make it hard to wake up. They’re also linked to feeling depressed, unfocused, and unmotivated.

High evening and nighttime cortisol levels result in insomnia and poor sleep.

If your cortisol curve is flattened out, you may experience fatigue during the day and difficulty sleeping at night.

An impaired response to stress can cause difficulty in solving problems and a feeling of burnout.

An exaggerated or prolonged stress response means you blow up quickly and have a hard time letting things go. When you get upset, you may feel the physical effects (like elevated heart-rate) and emotional effects for a long time afterward.

Cortisol’s Natural Rhythm

Because cortisol operates on a circadian or 24-hour cycle, your body uses environmental cues to know when to release cortisol.

Here are some examples of environmental signals that determine your daily cortisol rhythm:

  • Sunlight
  • Darkness
  • Artificial light
  • Meal timing

Think of these cues as setting your body’s clock, helping it determine how much cortisol to release during the day and night.

If you aren’t getting enough daytime sunlight, or if you are exposing your eyes and skin to artificial light at night when your body needs darkness, you may throw off your cortisol rhythm.

Eating late at night instead of during the day can also mess with your cortisol.

You can also have blunted or exaggerated cortisol responses as a result of chronic stress, anger issues, or post-traumatic stress disorder (PTSD).

You can end up feeling excessively stressed, burnt out, or unable to calm down after a high-stress period.


Normal and Degraded Cortisol Feedback Loops [*]

How to Test Cortisol Levels

If you think your cortisol is out of balance, particularly from chronic stress or burnout, it’s worth getting a cortisol test. You have four main options:

  • Saliva
  • Urine
  • Blood
  • Hair

Saliva Cortisol Tests

Saliva is the simplest way to test cortisol. It’s inexpensive, and the test results provide an immediate snapshot of your current levels.

Full day test kits like the ASI (Adrenal Stress Index) and Diurnal Cortisol CX4 are available for you to use at home. With full day saliva testing, you collect four separate saliva samples throughout the day to better understand your body’s cortisol rhythm.

Urine Cortisol Tests

Urine cortisol tests provide data similar to saliva cortisol tests, but also shed light on other stress hormone levels and cortisol metabolites. Urine tests are more expensive than saliva tests but may give you better insight into your stress hormone issues.

Blood Cortisol Tests

Cortisol blood testing usually isn’t as good a choice as saliva or urine. Blood cortisol levels don’t accurately reflect your current cortisol levels. Time of day is an essential element of cortisol levels; that’s why saliva or urine are usually better choices.

Unlike urine or saliva, most blood tests don’t demonstrate bioavailable cortisol either; they test total cortisol, most of which is in an inactive form. Blood tests work for demonstrating that your body can produce cortisol, but not for much else.

Hair Cortisol Tests

Hair cortisol testing is a newer test that offers insight into your cortisol levels going back months or even years.

In the future, hair testing may provide new insights into understanding health problems. As of right now, though, hair cortisol testing is still pretty experimental. You’re probably better off with a saliva or urine test.

If you’re on a tight budget and you don’t want to get tested, start by spending your money on positive lifestyle changes and healthy food.

You can still take plenty of positive steps to manage stress and balance your cortisol levels without testing.

How to Balance Your Cortisol

If your cortisol isn’t working properly, these tools can help you manage stress and get your cortisol back to where it should be.

Mindfulness and Stress Reduction

Mindfulness and other methods of stress reduction reduce cortisol immediately. They’re easy, and they cost you absolutely nothing.

If your cortisol is high all the time, or if your cortisol feedback loop is degraded, stress reduction is the best place to begin.

Consider the following methods for reducing cortisol:

methods for reducing cortisol

Deep Breathing

Slow, deep breathing reduces cortisol and improves your mood and cognition[*].

It’s easy to do — just sit still and breathe deeply into your belly, slowly inhaling for an 8-count, then exhaling for an 8-count. Repeat for 15 minutes.

It works immediately, and if you do it daily for a couple months, you’ll see a major decrease in your overall stress and cortisol levels.


Meditation is another excellent way you can reduce cortisol and better cope with stress.

In one meta-analysis of 45 studies, all types of meditation were found to lower cortisol, reduce stress levels, and improve other stress markers like blood pressure, heart rate, and even heart health[*].

Many styles of meditation are effective, so you can experiment to see which method you prefer. Headspace (paid) and Insight Timer (free) are two of the most popular mobile guided meditation apps.

Similar to deep breathing, you need to make a daily habit of meditation to get the full range of cortisol balancing benefits.

If you prefer not to sit still for 15-30 minutes at a time, you can reduce your cortisol and improve your stress response by doing yoga.


In terms of cortisol levels, blood pressure, heart rate, and other stress markers, yoga offers similar benefits to deep breathing and meditation[*].

You can do yoga solo or as part of a group, but for stress reduction, stick with more relaxed yoga styles, as opposed to power Vinyasa.

Become Aware Of Your Negative Thoughts

Thinking negative or worried thoughts about the future causes an immediate rise in cortisol[*]. If you have a constant negative internal dialogue going, you’ll have higher cortisol responses to stress[*].

Wellbeing and mental health affect physical health. You can address elevated cortisol levels by becoming aware of negative thoughts and putting them into perspective.

Positive Social Connections

You should also strive to keep friends and family around who care and are willing to listen to your worries and give you their perspectives. The payoff is lower cortisol levels and improved mental and physical health. A problem shared is a problem halved.

Physical and Emotional Intimacy

Being emotionally and physically close to a romantic partner is another excellent way to cope with stress[*].

A cortisol spike can reduce your libido, but even a small, intimate, nonverbal gesture — like a hug or a kiss — helps reduce cortisol responses in men and women in stressful situations. Touch also improves recovery time after a stressful event.

This is good to know if you’re around someone who’s scared or stressed out, too. Put a hand on their arm or shoulder, or (if you know them well enough) give the person a hug; it’ll help them relax.

Environment, Stress, and Circadian Rhythms

If you’re feeling stressed out all the time, you can also try changing your environment. Here are three proven ways you can balance cortisol production by altering your environment:

  • Go outside in nature
  • Get more sunlight and less artificial light
  • Develop effective morning and nighttime routines

Get Out in Nature

Living in an urban area can stress you out, but time in nature helps reverse the effect.

Japanese studies on “forest bathing” show that taking a walk outside in the forest helps reduce cortisol and related stress markers, whereas going for a walk in the city doesn’t have the same benefits.

A 13-year study with over 27,000 participants found that cortisol was lowest in summer, next-lowest in spring, higher in fall, and highest in winter[*]. The three major seasonal factors that affect cortisol are sunrise time, sunlight exposure, and length of the day[*].

Your body is built to spend time outside. Being indoors all the time results in disconnection from nature.

Get More Sunlight

To reconnect your body to nature and reduce your cortisol levels, go outside and get sun on your skin and in your eyes, no matter the season.

Morning sun is especially valuable to wake your body up and rebuild a healthy diurnal cortisol rhythm.

To maintain healthy circadian rhythms and prevent cortisol dysregulation, avoid artificial light whenever possible, especially at night. Artificial white or blue light at night confuses your body, disrupting the natural circadian rhythm of cortisol and melatonin[*].

Over time, artificial light at night causes cortisol problems, meaning poor sleep and daytime fatigue[*]. Poor circadian rhythm also makes it harder for you to process sugar, increases your blood sugar levels, and increases your risk of type 2 diabetes[*].

Getting infrared light from the sun can help you control cortisol without paying for pricey therapies like infrared saunas. Solar radiation at the earth’s surface is over 50% infrared light, which is one reason why sunlight is an excellent way to reduce and balance your cortisol levels.

Expose as much skin as possible when you’re out in the sun, and skip the sunscreen.

Instead, spend 10-30 minutes in direct sunlight (depending on how dark your skin is), and then put sunscreen on after that.

If you get a sunburn, you’ve gone too far — that’s when cancer risk increases. Near-infrared saunas are another way you can get infrared light.

Develop Healthy Routines

Eating late at night also contributes to poor circadian rhythm and throws off your cortisol levels[*].

To harness the power of light and circadian rhythms and positively influence your cortisol levels and stress response, design healthy routines around waking and bedtime:

  • Stick to consistent sleep and wake times
  • Get natural sunlight on your skin and eyes in the morning and throughout the day
  • Eat during daylight hours
  • Avoid artificial light at night and consider blue-blocking software or apps and glasses
  • Avoid mobile devices and other electronics 1-2 hours before bed

Consistent morning and nighttime routines will lower your cortisol levels, fix cortisol dysregulation, enhance your metabolic health, and help you sleep better.

Because poor sleep is another cause of cortisol problems, anything that improves your sleep quality is helpful to solve cortisol issues[*].

Exercise and Cortisol Levels

Working out can also help you regulate your cortisol levels[*]. In the short term, exercise acts as a stressor and temporarily elevates cortisol levels, but pays off by improving your overall resistance to stress[*].

If you have high cortisol levels, begin with light to moderate exercise. As you become more fit, your cortisol response will improve during and after exercise[*].

Cortisol and Caffeine

If you’re stressed out, don’t reach for coffee or energy drinks. Caffeine can increase cortisol levels, resulting in even more stress[*].

Sleep pressure is an automatic physical process that makes your body sleepy as night approaches. Caffeine disrupts sleep pressure, making it harder to get proper rest even when you need to sleep[*].

If you have high cortisol levels, dysregulated diurnal cortisol rhythms, or a degraded cortisol feedback loop, cut back on caffeine or avoid it altogether.

How Does Keto Affect Cortisol Levels?

Consuming a low-carb or ketogenic diet can have different effects on cortisol levels depending on factors like age, how long you’ve been doing keto, and whether or not you exercise regularly.

In one study of trained athletes in their late 20s, keto resulted in lower baseline levels of cortisol, with equivalent or higher cortisol levels during periods of exercise[*].

A study of non-athletic men in their early 20s exercising at various intensities in a ketogenic state showed that their insulin levels were lower and their cortisol levels were higher than on other diets[*].

The changes were likely due to their bodies meeting the requirement for glycolysis through gluconeogenesis.

If you exercise during carbohydrate restriction (like a keto diet), your body releases cortisol to help fuel the glycolytic (sugar metabolism) pathway through gluconeogenesis (making carbs from circulating or stored proteins).

Cortisol allows your body to preserve work capacity during ketosis[*]. Since exercising in a ketogenic state reduces your insulin levels, the combo of keto and exercise appears to be useful for preventing or reversing type 2 diabetes.

If you have high cortisol levels, starting a keto diet is a wise choice to lower your baseline cortisol. Keto may also help you recover from exercise by reducing cortisol.

Keto offers an advantage for endurance athletes through promoting the use of fat for fuel, which enhances aerobic efficiency and output.

For people just starting keto — especially seniors — using the other cortisol balancing techniques covered earlier in this article is an excellent idea, as there may be an initial elevation in cortisol levels.

Any elevation in cortisol from keto is probably temporary.

Cortisol Hormone: The Takeaway

Cortisol plays a vital role in your body’s stress response and daily functioning — but if your cortisol is too high, too low, or dysregulated, your mental and physical health will suffer.

Severe illness and chronic disease can result from cortisol imbalances.

In the modern world, most people live high-stress lifestyles, which can lead to high cortisol levels. High cortisol can cause burnout, fatigue, and even chronically low or dysregulated cortisol as time goes on.

If you are suffering from a cortisol problem, you can enhance your health by testing your levels and experimenting with safe, proven methods for reducing and rebalancing cortisol.


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