The Hidden Cost of Stress: Understanding Low Cortisol and Adrenal Burnout

In our fast-paced, always-on world, chronic stress has become a silent epidemic. While most of us associate stress with high cortisol, few realize that prolonged stress can eventually lead to low cortisol levels, sometimes referred to as adrenal fatigue or adrenal burnout. This condition can quietly erode health, leaving people feeling drained, anxious, and foggy—even after a full night’s sleep.

What Is Cortisol?

Cortisol is a steroid hormone produced by the adrenal glands in response to stress and low blood glucose. It plays a crucial role in:

• Regulating metabolism

• Managing immune response

• Supporting cardiovascular function

• Balancing blood sugar

• Modulating the stress response (via the HPA axis)

Cortisol follows a diurnal rhythm, peaking in the early morning and tapering off throughout the day. But when stress becomes chronic, this rhythm can become disrupted.

Symptoms of Low Cortisol

When cortisol levels drop too low—especially after a period of chronic overproduction—the body begins to malfunction in subtle but significant ways. Peer-reviewed literature identifies the following common symptoms of hypocortisolism [1,2]:

• Persistent fatigue (despite rest)

• Brain fog and poor concentration

• Low blood pressure or dizziness when standing

• Salt cravings

• Decreased libido

• Mood swings or depression

• Sleep disturbances (especially waking up at night)

• Low stress tolerance

• Unexplained weight loss or muscle weakness

• Frequent infections due to a weakened immune system

Chronic Stress and the Cortisol Curve

The body’s stress response is governed by the HPA axis (hypothalamic-pituitary-adrenal). In the early stages of chronic stress, cortisol levels rise as the body attempts to maintain equilibrium.

But over time, allostatic load (the cumulative burden of chronic stress) exhausts the HPA axis. Eventually, the brain downregulates cortisol production.

This adaptation, while protective in the short term, impairs the body’s ability to respond to future stress.

What About Adrenal Fatigue?

“Adrenal fatigue” is a popular term in functional medicine, though it's not widely recognized by conventional endocrinology. However, the concept aligns with well-documented dysfunctions of the HPA axis and low cortisol output. Conditions like non-classic adrenal insufficiency or HPA axis dysfunction are used in scientific literature to describe similar phenomena.

Diagnosing Low Cortisol

Testing for cortisol dysregulation can include:

• Salivary cortisol (multiple times per day to track circadian rhythm)

• 24-hour urinary free cortisol

• AM serum cortisol (blood test)

• ACTH stimulation test (to assess adrenal reserve)

Note: Diagnosis and interpretation should be done by a trained practitioner.

How to Restore Healthy Cortisol Levels

1. Address the Root Causes of Stress

• Sleep hygiene (7–9 hours/night; consistent schedule)

• Reduce stimulants (caffeine, especially in the afternoon)

• Practice mindfulness (meditation, deep breathing, yoga)

• Light exposure in the morning to reset circadian rhythm

• Exercise wisely: Avoid overtraining—opt for strength training, walking, or gentle cardio

2. Nutrition for Adrenal Support

• Eat balanced meals with protein, fat, and fiber

• Avoid blood sugar crashes (skip refined sugar, high-carb snacks)

• Ensure electrolyte balance: sodium, potassium, magnesium

• Stay well-hydrated

Supplements Backed by Science

1. Adaptogenic Herbs

These herbs help modulate the HPA axis and improve resilience to stress:

• Ashwagandha – Shown to reduce cortisol and improve fatigue and anxiety.

• Rhodiola rosea – Increases energy, improves cognitive function, and reduces fatigue.

• Holy Basil – May reduce stress and support cortisol balance.

2. Phosphatidylserine

A phospholipid that has been shown to blunt cortisol response to acute stress and support cognitive function.

3. Vitamin C

The adrenal glands have one of the highest concentrations of vitamin C in the body. Supplementation may help reduce cortisol and oxidative stress.

4. Magnesium

Essential for over 300 enzymatic processes; magnesium deficiency increases cortisol production and sensitivity to stress.

5. B-Vitamins (especially B5, B6, and B12)

Crucial cofactors in adrenal hormone synthesis. Supplementation may improve mood and energy.

6. Licorice Root (Glycyrrhiza glabra)

Slows the breakdown of cortisol in the liver and can temporarily increase circulating cortisol levels. Use cautiously and under medical supervision, especially in cases of high blood pressure. I would only recommend this after being assessed by a practitioner and confirmed that cortisol levels need to be increased. 

When to Seek Help

If you suspect you have low cortisol or symptoms of adrenal dysfunction, it’s important to consult a qualified provider. Left unchecked, this condition can worsen and contribute to more serious illnesses like autoimmune disease, chronic fatigue syndrome, or depression.

Conclusion

Low cortisol is a sign that the body has been under siege for too long. While it may not always be acknowledged in conventional medicine, its effects are real—and reversible with the right support.

The key lies in nourishing your body, calming your mind, and giving your adrenals time to recover. With a combination of lifestyle changes, targeted supplementation, and professional guidance, you can restore balance and feel like yourself again.