It’s rare to meet someone who isn’t affected by our fast-paced, stressful times. As many as 60-80% of doctor's visits may have a stress-related component, although very few office visits include stress management counseling.
While stress is a natural response to life’s challenges, long-term stress can wreak havoc on our bodies.
Stress hormones are produced by the adrenal glands, which are small, triangular glands on top of the kidneys. Adrenal glands produce hormones like cortisol and DHEA and neurotransmitters like norepinephrine and epinephrine which help regulate stress, metabolism, and immune response.
Chronic adrenal imbalance, often caused by prolonged stress, can lead to symptoms such as fatigue, mood swings, sleep disturbances and hormonal issues, and may even cause serious health complications.
For many people, understanding their adrenal health is foundational for addressing issues like fatigue, sleep disturbances, hormone imbalances, and even mood disorders.
This is where adrenal testing comes in. Functional medicine practitioners often order adrenal tests to get a detailed view of how the adrenal glands are functioning and to guide treatment decisions that address the root causes of stress-related health problems.
In this article, we’ll discuss reasons to consider adrenal testing and explore the most commonly ordered adrenal tests in functional medicine, helping both patients and practitioners understand when and why to use them.
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The HPA Axis and Adrenal Health
To understand why adrenal testing is so important, we first need to look at the HPA axis: the Hypothalamic-Pituitary-Adrenal axis. The HPA axis is a complex communication system between the brain and the adrenal glands that regulates our response to stress.
When we experience stress, the hypothalamus in the brain sends a signal to the pituitary gland, which in turn signals the adrenal glands to release stress hormones, including cortisol, the body’s primary stress hormone.
Cortisol helps the body handle short-term stress by increasing energy, reducing inflammation, and helping us stay alert. However, when stress becomes chronic, the HPA axis can become dysregulated.
This leads to problems with adrenal hormone production—either too much or too little—resulting in symptoms like fatigue, mood swings, brain fog, and immune system dysfunction.
Regulating hormone levels, including thyroid and sex hormones, begins with healthy adrenal glands, as we’ll see.
Why Functional Medicine Practitioners Value Adrenal Testing
In functional medicine, the goal is to address the root causes of health issues, not just manage symptoms. Adrenal testing is a key part of this approach because it provides valuable insights into how stress is affecting the body.
By measuring cortisol and other hormones, functional medicine practitioners can assess the health of the HPA axis and adrenal glands.
This helps guide personalized treatment plans that address both the physical and emotional toll of chronic stress, leading to better long-term outcomes for fatigue, hormone imbalances, and more.
Let’s now dive into the 6 most common adrenal tests that functional medicine practitioners use to assess adrenal health.
1. Adrenal Stress Index (ASI)
The Adrenal Stress Index is a simple, non-invasive test that measures cortisol levels throughout the day using saliva samples.
Typically, cortisol is measured at four key times: morning, noon, evening, and night. This provides a clear picture of your body’s diurnal, or daily, cortisol rhythm, which can show whether your cortisol is too high, too low, or out of sync with an expected daily pattern.
The Adrenal Stress Index often includes a measurement of DHEA or DHEA-S (dehydroepiandrosterone or its sulfated form, DHEA-sulfate), another hormone produced by the adrenal glands. DHEA is important in the stress response, in aging, and in hormone regulation.
Low levels of DHEA are often seen in people with chronic stress and adrenal fatigue. By assessing both cortisol and DHEA levels, practitioners can get a fuller picture of adrenal health.
When to Order
An Adrenal Stress Index is commonly ordered for people experiencing chronic fatigue, burnout, anxiety, or sleep disturbances. It is also helpful for those who suspect they may have adrenal fatigue or HPA axis dysregulation because it can identify changes in the daily rhythms of cortisol.
DHEA is another marker for chronic stress exposure; while DHEA doesn’t follow the same daily changes as cortisol, it can be used to assess the adrenal gland’s response to stress.
How Results Guide Treatment
Based on the results, a functional medicine practitioner might recommend adrenal support supplements like adaptogenic herbs, DHEA supplementation, or lifestyle changes such as improving sleep hygiene and stress management.
2. Cortisol Awakening Response (CAR)
The Cortisol Awakening Response (CAR) is the natural rise in cortisol levels within the first hour after waking, typically peaking about 30 minutes after waking and then returning to baseline within about 60 minutes of waking. This cortisol rise is intended to prepare you for your day.
The CAR reflects the function of the hypothalamic-pituitary-adrenal (HPA) axis. By measuring cortisol at key intervals after waking, the CAR provides insight into your body’s baseline stress regulation and adaptation.
A healthy CAR indicates proper HPA axis function, while a blunted or exaggerated CAR is associated with chronic stress, PTSD, depression, burnout, and even cardiovascular and autoimmune conditions. Testing the CAR helps identify HPA axis dysregulation and its broader effects on hormone balance.
Why CAR is a Good Assessment of HPA Axis Function
The CAR helps us understand how the HPA axis functions daily and how it responds to stress. When the CAR is too low or too high, it has been linked to chronic stress and mental health issues like depression and PTSD, and alterations in the daily rhythm of cortisol.
When to Order
This test is particularly useful for people who wake up feeling tired or who experience significant stress. It’s also helpful for those with mood disorders or resilience issues.
How Results Guide Treatment
If the CAR is abnormal, practitioners may recommend strategies to support the HPA axis, such as stress-reduction techniques, morning sunlight exposure, or specific adaptogenic herbs.
Additionally, understanding the unique stressors in the patient’s life and supporting lifestyle change and habits that increase resilience should be considered. Working with a therapist or counselor may provide benefit for people with chronic stress and mental health concerns.
3. Comprehensive Hormone Panel
Adrenal function is closely tied to overall hormone balance, including sex hormones like estrogen, progesterone, and testosterone.
The adrenal glands produce DHEA, an androgen and precursor to other sex hormones, so adrenal dysfunction can lead to hormonal imbalances that affect reproductive health, stress response, and energy levels.
Cortisol is also produced from progesterone and common precursors, so stress also affects progesterone levels.
The DUTCH (Dried Urine Test for Comprehensive Hormones) Plus test is one of the most comprehensive hormone panels available in functional medicine.
It measures cortisol, cortisone, DHEA, as well as sex hormones like estrogen, progesterone and testosterone and their metabolites.
The DUTCH Plus test also tests melatonin levels and some organic acids, shedding light on factors like nutrient status, inflammation, and sleep quality.
Why Melatonin Matters
Melatonin is a hormone that regulates the sleep-wake cycle. Since chronic stress and cortisol imbalances can disrupt sleep patterns, assessing melatonin levels can further guide treatment for people with chronic stress and poor sleep quality.
When to Order
A comprehensive hormone panel is often ordered for people experiencing hormonal imbalances, adrenal fatigue, perimenopause, or sleep disturbances.
How Results Guide Treatment
Treatment based on these results might include hormone therapy, melatonin supplementation, or targeted adrenal support to help regulate the production and release of adrenal hormones and support other hormones as well.
4. Neurotransmitter Testing
Neurotransmitter testing measures levels of chemicals like serotonin, dopamine, GABA, and norepinephrine which are important in mood, stress response and recovery, and overall mental health.
The neurotransmitters norepinephrine and epinephrine are also produced in the adrenal glands.
Why Neurotransmitter Testing Matters for Adrenal Health
Adrenal health and mental health are closely connected. Changes in cortisol levels can affect brain function, as seen in conditions like Addison’s disease. Alterations in the CAR are also commonly seen in mental health conditions like depression and PTSD.
Testing stress-related neurotransmitters like norepinephrine and epinephrine may also show how well the adrenals are functioning under stress.
Alterations in expected epinephrine or norepinephrine levels can be seen in stress, excessive stimulant use including coffee, hypoglycemia, and certain nutrient deficiencies, and may cause feelings of stress and anxiety.
It’s important to understand that neurotransmitter testing does not directly test neurotransmitter levels inside the brain. However, because neurotransmitters can cross the blood-brain barrier, urinary neurotransmitter testing does show both peripheral (outside the brain) and central (inside the brain and central nervous system) levels.
Although the exact connection between neurotransmitter activity in the central nervous system (CNS) and levels found in urine is not fully understood, some studies show a correlation.
This suggests that measuring neurotransmitters in urine could be useful as biomarkers for certain psychiatric and inflammatory conditions.
When to Order
This test may be helpful for people struggling with anxiety, depression, or other mental health conditions in the setting of chronic stress.
How Results Guide Treatment
Treatment may include dietary and lifestyle adjustments; counseling or therapy for mental health; and stress management techniques to support mental and adrenal health. Nutrient deficiencies, excessive stimulant use, and undereating should be addressed if necessary.
5. Micronutrient Testing
Micronutrients are essential for supporting adrenal function, especially during times of stress, when the body uses more vitamins and minerals than normal.
Key nutrients required for adrenal health include:
Zinc: regulates adrenal hormone release, supports immune function, and is anti-inflammatory.
Magnesium: involved in stress response regulation and prevents adrenal fatigue.
B Vitamins:
- B5 (Pantothenic acid): required for cortisol production.
- B6 (Pyridoxine): supports neurotransmitter synthesis, helping modulate stress.
Amino Acids:
- Tyrosine: precursor to adrenaline and norepinephrine, supporting energy and mental clarity.
- Tryptophan: supports serotonin production, aiding in stress management.
Vitamin C: essential for adrenal hormone synthesis, vitamin C is stored in high concentrations in the adrenal glands.
Selenium: supports thyroid function, closely linked to adrenal health; selenium also boosts antioxidant capacity to reduce inflammation, which is an adrenal stressor.
Testing for these nutrients helps identify deficiencies and guide supplementation for improved adrenal function.
6. Thyroid Testing
Adrenal and thyroid function are closely interconnected, and both affect energy and metabolism.
The thyroid regulates the cellular metabolic rate, while the adrenal glands produce stress hormones that affect blood sugar and insulin sensitivity, key markers of metabolic health.
When one system is out of balance, it can affect the other, and thyroid-adrenal dysregulation can cause or worsen fatigue.
The Connection Between Adrenal and Thyroid Function
Chronic adrenal stress can lead to decreased thyroid function, resulting in symptoms of hypothyroidism.
Conversely, thyroid dysfunction can strain the adrenals, as the body struggles to manage metabolism and stress simultaneously.
Hypothyroidism and adrenal stress can look similar: for example, fatigue, weight gain, depression, and sleep problems can be seen in both conditions.
Testing both systems together provides a more complete picture of hormonal health and can help differentiate the two.
When to Order
Thyroid testing is recommended for people with suspected adrenal fatigue, thyroid issues, or chronic fatigue.
How Results Guide Treatment
Treatment might include thyroid hormone support, adrenal supplements, or lifestyle modifications to balance both systems.
Saliva vs. Urine vs. Blood Testing for Adrenal Function
There are several methods for testing adrenal hormones, each with its own strengths and limitations.
Saliva Tests
Ideal for measuring cortisol patterns throughout the day. Non-invasive and often used for tracking diurnal cortisol rhythm.
Salivary cortisol testing has shown strong correlation with serum cortisol levels, making it a viable option for detecting adrenal imbalances.
Best For:
Chronic stress, adrenal fatigue, or when a daily cortisol pattern is needed.
Urine Tests
Provides the opportunity for a comprehensive look at cortisol, cortisone, as well as metabolized cortisol and cortisone for a complete assessment of adrenal hormone production and processing.
Best For:
Shows total cortisol output during a 24 hour period, as well as how cortisol is processed in the body to determine whether symptoms are due to decreased cortisol production, increased cortisol breakdown or inactivation, or whether other body systems need to be assessed.
Blood Tests
Blood tests measure cortisol levels at a single point in time and don’t show diurnal patterns.
Blood tests only check free, or unbound, cortisol—the part not attached to a binding protein. Since cortisol travels in the blood bound to proteins, these tests don’t measure the bound portion of cortisol in the bloodstream. This can miss total cortisol levels, and changes in the amount of binding proteins in the body.
Best For:
People needing a quick snapshot, or when other blood tests like ACTH will be done to diagnose endocrine disease.
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Key Takeaways
Several functional medicine tests are available to assess a patient’s stress response. Knowing when to use each type of test helps practitioners choose the right method for the patient's needs.