The Cortisol Hormone: What It Is, What It Does, and How to Regulate It

The Cortisol Hormone: What It Is, What It Does, and How to Regulate It

The cortisol hormone is one of the most important hormones in the human body and it affects nearly every tissue and organ. You may also know cortisol as the "stress hormone". Cortisol is responsible for a wide range of functions including metabolism, stress response, and energy production.

In this blog post, we will discuss what the cortisol hormone is, what it does, and how you can regulate it. We will also explore how to test cortisol levels and provide some tips for reducing cortisol levels if they are too high and increasing them if they are too low.

What is cortisol?

Glucocorticoid hormone and the sleep-wake cycle

Cortisol is a glucocorticoid hormone, or steroid hormone, that is produced by the adrenal gland. Glucocorticoids suppress inflammation in the body's tissues and control metabolism in your muscles, liver, fat, and bones. Glucocorticoids also affect your sleep-wake cycle, which is the daily pattern that your body experiences in terms of sleep and wakefulness. This pattern determines when your body should be awake and when it should be sleeping. The ideal sleep-wake cycle consists of 15-17 hours of being awake, followed by 7-9 hours of sleep.

Fight or flight response

Cortisol's main function is to regulate your body's response to stress. It does this by affecting the body's fight-or-flight response, which is the body's natural reaction to a perceived threat.

The body processes stressful information and elicits a response depending on the degree of the threat. The body's autonomic nervous system is broken down into the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). In times of stress, the SNS gets activated, and cortisol is released. The SNS is responsible for the fight or flight response, which causes a cascade of hormonal and physiological responses.

Cortisol levels increase when you are under stress, and they help your body to deal with the stressor by preparing you for action. Cortisol levels typically peak in the morning and then decline throughout the day.


Cortisol levels increase in response to physical or psychological stressors like exercise, injury, illness, emotional stress, stressful events, or general life stressors. When cortisol levels remain elevated for long periods of time, it can lead to a condition known as "chronic stress." This can result in a number of health problems including weight gain, anxiety, depression, and even heart disease.

This hormone has been coined as the "public health enemy" due to the fact that so many adults in the United States suffer from chronic stress. A survey conducted by the American Psychological Association found that 42% of adults in the U.S. reported feeling more stressed than they did the year before, and 64% said their stress levels had increased in the past five years.

What does cortisol do?

Cortisol plays a very important role in the body's stress response. When you are under stress, cortisol levels increase, and this hormone helps to prepare your body for the "fight or flight" response. Cortisol levels also increase in response to physical exertion, during illness or injury, or during emotional distress. In addition to its role in the stress response, cortisol levels also influence memory and learning.

Cortisol helps regulate:

  • Your body's response to stress
  • Homeostasis, or balance in the body
  • Metabolism
  • Blood sugar levels
  • Blood pressure
  • Sleep
  • Your mood
  • Energy levels
  • Your immune system
  • Body's use of fat and protein for energy production

Cortisol is essential for survival, but when levels are too high, it can lead to some negative health effects and really impact the body.

What can cortisol do to the brain?

Christopher Bergland from Psychology Today wrote, “Cortisol is believed to create a domino effect that hard-wires pathways between the hippocampus and amygdala in a way that might create a vicious cycle by creating a brain that becomes predisposed to be in a constant state of fight-or-flight."

In other words, cortisol can lead to changes in the brain that make it more difficult to cope with stress over time. This can result in a number of problems including anxiety, depression, and even memory problems.

High cortisol levels

Excess cortisol production can create many health problems and can even affect your mental health. High levels may feel like constant stress and fear- like your body is never able to wind down. You may feel anxious, irritable, or have difficulty sleeping. You may also have a hard time concentrating or remembering things.

Some of the main problems associated with high cortisol levels can include:

  • Anxiety
  • Depression
  • Digestive system problems
  • Rapid weight gain
  • Headaches
  • High blood pressure
  • High blood sugar (cortisol suppresses insulin)
  • Memory and learning difficulties
  • Muscle tension
  • Sleep problems that can lead to chronic sleep issues
  • Suppressed immune system function
  • Cushing's syndrome (a rare condition that results from prolonged exposure to high cortisol levels)

More extreme cases of high cortisol can lead to Cushing syndrome, which occurs when the human body is exposed to high cortisol levels for an extended period of time. This can also lead to a pituitary tumor. These are noncancerous but can still cause damage. Read more about them here.

The Cortisol Hormone: What It Is, What It Does, and How to Regulate It

Tips to reduce cortisol levels

Chronic stress puts pressure on the body as a whole, and it is extremely likely that your body will respond negatively. Though the list of side effects is long and scary, there are many things we can do to regulate our cortisol levels and keep them in check. 

If you think your cortisol levels may be too high, here are some lifestyle changes you can make to help reduce them:

-Exercise regularly: Exercise can help reduce stress and cortisol levels.

-Get enough sleep: Sleep is important for overall health and can help reduce stress levels. Getting 7-9 hours of sleep also keeps your sleep-wake cycle in check. Try to fall asleep and wake up at the same time every day! This isn't always possible with busy schedules but keeping a consistent sleep schedule has proved to be awesome for feeling well rested, sleep quality, and reducing cortisol levels.

-Eat a healthy diet: Eating a healthy diet can help reduce cortisol levels. Dark chocolate, basil, dried apricots, garlic, asparagus, avocado, leafy greens, salmon, blueberries, and broccoli are great options to help reduce cortisol levels.

-Manage stress: Managing stress can help reduce cortisol levels. This may look like saying "no" to a night out with friends and saying yes to a night alone reading a book in the bathtub eating some dark chocolate. Try winding down at night by taking an hour off of electronics and going for a walk or waking up early to find some alone time. 

-Reduce alcohol intake: Alcohol can increase cortisol levels. If you're struggling with too much cortisol, consider your alcohol intake and adjust accordingly.

-Limit caffeine intake: Caffeine can increase cortisol levels. Opt-in for a decaf from Starbucks instead of your double shot espresso drink. Maybe even replace your coffee and caffeinated beverages with some H2O!

Low cortisol levels

Too little cortisol can also be problematic, and this happens when your adrenal glands don't produce enough cortisol.

Because this hormone plays a vital role in keeping your body alert, low levels can be easy detectible by fatigue and dizziness. Low levels can also lead to low blood pressure, skin problems, sexual disorders, tiredness, weakness within the body, or depression. It can cause weight loss, decreased appetite, and low blood sugar levels. You may also have trouble sleeping or concentrating. Overall, the body may show an overall caste of dullness.

About 100,000 people in the United States have a condition called Addison's disease, or primary adrenal insufficiency, in which the body does not make enough cortisol. Symptoms of this may include weight loss, chronic fatigue, dizziness, darkening scars, muscle weakness, gastrointestinal issues, and low blood sugar. If you suspect you may have this, consider visiting a healthcare provider immediately.

Tips to increase cortisol levels

If you think your cortisol levels may be low, here are some tips to help increase them:

-Get enough protein: Protein helps the adrenal glands function properly. Consider adding more chicken, fish, eggs, and beans to your diet.

-Add healthy fats to your diet: Healthy fats like avocados, olive oil, nuts, and seeds help the adrenal glands function properly.

-Reduce stress: Stress can lead to low cortisol levels. Consider adding some relaxation techniques to your routine like yoga, meditation, or aromatherapy.

-Get enough sleep: Sleep is important for overall health and can help reduce stress levels. Getting at least 7-9 hours of sleep every night can help increase cortisol levels.

-Exercise: Exercise can help increase cortisol levels. Consider adding some moderate exercise to your routine like walking, biking, or swimming. Stay away from rigorous activity like kickboxing, sprinting, and HIIT workouts.

Overall cortisol level maintenance

You can help regulate cortisol levels by managing stress, getting enough sleep, and eating a healthy diet. You can also take supplements like magnesium or omega-three fatty acids, which have been shown to help lower and maintain cortisol levels to keep them at a healthy level.

Getting your cortisol levels tested

If you think you may have high or low cortisol levels, it's important to speak with a doctor. They can order a cortisol test to determine if your levels are off and help you find a treatment plan that's right for you. There is medication for cortisol issues as well. 

Many clinics and healthcare facilities can do a cortisol test. A cortisol test measures the level of cortisol in your blood, saliva, or urine. This test is usually done in the morning, when cortisol levels are highest.

Cortisol is a hormone that's essential for our survival, but when it's out of balance, it can cause some serious problems. By understanding what cortisol is, what it does, and how to regulate it, we can take steps to keep our cortisol levels in check and maintain our overall health and well-being.


What questions do you have about cortisol? Send your messages to us on Instagram @garnuu and give us a follow! And be sure to check out our other blog posts on hormones and women's health. 

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-Garnuu Team


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