Always Tired? This Hormone Might Be to Blame

Always Tired? This Hormone Might Be to Blame

These days, talk of cortisol, also known as the "stress hormone," has been on the rise. You can hardly have a chat with friends without someone lamenting that their cortisol has been spiking hard lately. And, it's no wonder: We live in a hyper-stimulating world with plenty of stresses to navigate. That can leave us feeling anxious, exhausted... or everyone's favorite—both! While cortisol does play a significant role in our body's stress response, its impact on our energy levels is equally profound. Understanding how cortisol works can help us find the balance that keeps us feeling our best. 

The science of cortisol

Cortisol, a steroid hormone that belongs to a class of hormones called glucocorticoids, is produced by the small organs located on top of your kidneys called  adrenal glands. Cortisol's primary functions are to increase blood sugar through gluconeogenesis, suppress or boost the immune system, and aid in the metabolism of fat, protein, and carbohydrates. Overall, it helps the body manage and utilize energy efficiently.

Under normal circumstances, cortisol levels follow a diurnal rhythm, peaking in the early morning to help us wake up and gradually declining throughout the day to get us ready for sleep. This natural rhythm aligns with our body's energy needs, providing a burst of energy when we need it and allowing us to rest and recuperate at night.1

How are energy levels impacted by cortisol?

When everything is in balance, cortisol supports our energy levels. It helps us feel awake and alert in the morning, keeps our blood sugar stable, and supports our metabolic processes. However, problems arise when cortisol levels are either too high or too low.

"Generally, a cortisol imbalance can come about due to extremely high stress or prolonged stress," says Melissa Groves Azzaro, a registered dietitian and author of A Balanced Approach to PCOS. "While there are clinical diagnoses of high (Cushing syndrome) and low (Addison's disease), which require medical treatment, there is a large spectrum of 'out of range' cortisol levels or inappropriate cortisol patterns that can affect our day-to-day lives," she explains.2

Understanding high cortisol levels

When you encounter stress, your body might release cortisol after releasing adrenaline, also known as our “fight or flight” hormone. Chronic stress, poor sleep, and unhealthy lifestyle habits can lead to consistently elevated cortisol levels. When cortisol is high, it can make you feel wired and anxious, yet also drained. Imagine your body trapped in a state of perpetual high alert. To no one's surprise, this can be exhausting over time. Our body must be able to drop into more relaxed states, which allow our parasympathetic nervous system (also known as our "rest and digest" system) to do its job. And it's an important job: The parasympathetic nervous system's main functions are to conserve energy, regulate bodily functions, and maintain the integrity of organs, tissues, and cells.

One study found that chronic stress leads to sustained high cortisol levels, which can disrupt sleep patterns and contribute to insomnia.3  Poor sleep further exacerbates fatigue, creating a cycle of exhaustion. Additionally, elevated cortisol can cause blood sugar imbalances, leading to energy crashes and cravings for sugary foods, which provide a quick but short-lived energy boost.

In short spurts, cortisol can boost immunity by reducing inflammation. Chronic elevations, however, can lead to the immune system becoming resistant, which can suppress its ability to fight off invaders. This can happen when the body gets used to having too much cortisol in the blood over time. High cortisol levels can also lead to an accumulation of stress hormones and increased production of inflammatory cytokines, which further compromise the immune response.

Symptoms of high cortisol include:

  • Weight gain, especially in the abdominal area
  • Anxiety and irritability
  • Trouble falling asleep and staying asleep
  • Nervousness 
  • Shakiness
  • High heart rate
  • Blood sugar and blood pressure instability

While discussing cortisol, it's important to highlight Cushing syndrome, a condition characterized by chronically elevated cortisol levels. This syndrome can result from prolonged use of corticosteroid medication or, more rarely, from a cortisol-producing tumor in the adrenal glands or a tumor elsewhere in the body that stimulates cortisol production. Symptoms of Cushing syndrome include rapid weight gain, particularly around the abdomen and face, high blood pressure, osteoporosis, muscle weakness, and severe fatigue. The excess cortisol disrupts normal metabolic processes and immune function, leading to increased susceptibility to infections and slower healing. Managing Cushing syndrome often involves treating the underlying cause, whether adjusting medication use or surgically removing a tumor, and it requires careful medical supervision to restore hormonal balance and alleviate symptoms. Understanding and addressing this condition is crucial for those affected to regain their energy and overall health.

Understanding low cortisol levels

On the flip side, chronically low cortisol levels can be equally problematic. This condition is often referred to as adrenal fatigue, though it's more accurately described as hypothalamic-pituitary-adrenal (HPA) axis dysregulation.3  When the adrenal glands are overworked from prolonged stress, they can struggle to produce adequate cortisol.

Symptoms of low cortisol include chronic fatigue, low blood pressure, muscle weakness, and a general sense of malaise. One study demonstrated that individuals with low cortisol levels report higher levels of fatigue and have a reduced ability to handle stress.4 Without enough cortisol, the body struggles to maintain stable blood sugar levels, leading to persistent tiredness and lack of energy.

Other symptoms of low cortisol include:

  • All-day low energy
  • Feeling "wired but tired" 
  • Severe fatigue and lack of focus
  • Sugar and salt cravings
  • Apathy
  • Low libido 
  • Memory problems 

What about adrenal fatigue?

A general term used to describe a group of symptoms, adrenal fatigue is thought to occur when ongoing fight-or-flight state in the body leaves the adrenal glands lagging. Examples of those symptoms include tiredness, weakness, sleep problems.

Supporting healthy cortisol levels

Maintaining balanced cortisol levels is crucial for sustaining energy and overall well-being. Here are some evidence-based strategies to help regulate cortisol and boost your energy levels:

1. Prioritize your sleep 

7-9 hours of quality sleep per night is the gold standard. If you struggle with sleep, it's a good idea to establish a regular sleep routine by winding down, going to bed and waking up at the same time each day. Pre-sleep rituals help signal your body that it's time to turn in for the night. Screens and stimulants can interfere with your natural cortisol rhythm, so it's best to steer clear.5

2. Manage your stress

Practices such as mindfulness meditation, yoga, and deep breathing exercises have been shown to lower cortisol levels. One study found that mindfulness meditation significantly reduces cortisol and improves overall emotional well-being.6 Another study found that cortisol levels were lower after participants engaged in just 45 minutes of art making.

3. Eat a healthy diet

Consuming a diet rich in whole foods, including plenty of fruits, vegetables, lean proteins, and healthy fats can help stabilize blood sugar levels and support adrenal function. Excessive sugar and refined carbohydrates, which can cause blood sugar spikes and crashes, may contribute to energy slumps.5

4. Exercise regularly

Regular physical activity helps regulate cortisol levels. A mix of cardiovascular exercise, strength training, and relaxation exercises like yoga is a great goal to work towards. However, be mindful not to overtrain, as excessive exercise can elevate cortisol levels.5

5. Hydrate yourself

Dehydration can also stress the body and elevate cortisol levels. Ensure you're drinking enough water throughout the day to stay properly hydrated.5

6. Limit coffee and alcohol

Too much caffeine and alcohol can disrupt cortisol rhythms and negatively impact sleep.5 If you tend to overdo it on either, try to moderate your intake for a few weeks and see how you feel. Sometimes, the positive difference is enough of a motivation to make a change.

7. Cultivate a healthy gut microbiome

In one study, participants who consumed a daily probiotic drink saw significantly lower cortisol levels than the control group after 12 weeks. To improve your gut health, focus on eating a diet rich in fruits, vegetables, legumes, nuts and seeds, and whole grains, and consider taking a daily probiotic.5

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Balancing cortisol levels also involves regulating the nervous system, particularly the autonomic nervous system, which includes the sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) branches. Chronic stress keeps the sympathetic nervous system activated, leading to continuous cortisol release. Techniques to activate the parasympathetic nervous system can help counteract this and promote cortisol balance. Practices such as deep breathing exercises, progressive muscle relaxation, and biofeedback can calm the nervous system, reducing stress and lowering cortisol levels. Engaging in regular mindfulness meditation has been shown to enhance parasympathetic activity, fostering a state of relaxation and resilience against stress. By intentionally regulating the nervous system, you can create an internal environment that supports balanced cortisol production, ultimately promoting better energy levels, improved mood, and overall well-being.

Remember, it's not just about reducing cortisol but ensuring it follows its natural rhythm. When cortisol is in harmony, so are we, ready to face the day with vigor and rest peacefully at night. Embrace cortisol with care, and it will take care of you.

Up next: Learn what foods to eat to help balance your hormones, plus, learn how to balance your hormones postpartum.


  1. Interactions between sleep, stress, and metabolism: From physiological to pathological conditions
  2. Stressed out and exhausted? You might have a cortisol imbalance
  3. A new model for the HPA axis explains dysregulation of stress hormones on the timescale of weeks
  4. The impact of stress on sleep: Pathogenic sleep reactivity as a vulnerability to insomnia and circadian disorders
  5. How to lower your cortisol levels
  6. Effects of Mindfulness on Psychological Health: A Review of Empirical Studies
  7. Daily administration of paraprobiotic Lactobacillus gasseri CP2305 ameliorates chronic stress-associated symptoms