Adrenal fatigue – is it really a thing?

The so-called diagnosis of adrenal fatigue is often brushed off by many medical professionals as something made up by alternative health care practitioners such as ND’s, functional medicine MD’s and others. Alternative health care practitioners and patients alike get frustrated as the only adrenal disorders acknowledged in conventional medicine are extreme diseases such as Addison’s or Cushing’s. So whats the deal? Do adrenals really get fatigued?

Male adrenal anatomyFirst let’s get clear on our terminology and understanding of some important organs involved in the management of stress and hormones:

  • Adrenals are small glands that sit above the kidneys. They respond to signals from your brain about stress. They are responsible for secreting stress hormones (cortisol, epinephrine, norepinephrine), aldosterone and as well as small amounts of estrogen, progesterone and testosterone.
  • Cortisol is a stress hormone released in response to perceived stress as well as to low blood sugar levels. It has several functions explained below.
  • Hypothalamus & Pituitary are structures in the brain that functions in linking the nervous system to the hormonal (endocrine) system. Hormones are released from the hypothalamus to stimulate or inhibit the pituitary’s release of hormones that help to regulate hormonal functions in the rest of the body.
What’s the story with cortisol?

Cortisol is an extremely important hormone in the body. You need it to survive. As simple as that. It does a lot of things in the body, the main functions are summarized here:

Functions of Cortisol
  • Regulation of blood sugar
  • Fat, protein and carbohydrate metabolism
  • Regulation of immune function and inflammation
  • Has cardiovascular effects (blood pressure)
  • Has effects on the central nervous system

Cortisol has gotten a lot of bad press. Too much is bad for your health. That part is well understood. It’s easy to grasp that concept which was so well explained by Hans Selye (3). You experience a stressor and your brain releases a hormone to tell your adrenals to release cortisol. If you experience this stressor repeatedly and have minimal ways to mitigate the stress (high pressure job or family stresses) then the cortisol may remain high with little chance of recovering to normal levels. This of course has numerous negative effects on health that have been documented well.

What is less well understood is that many people actually experience chronically low cortisol output. This is when practitioners will start using the term adrenal fatigue, where it is thought the adrenals are literally burned out from years of chronic stress and excessive cortisol output. But is this really accurate? In truth this term more explains how a person feels. They feel burned out, exhausted, tired, anxious, depressed, can’t take it anymore.

I think we are projecting our emotional states onto our adrenals.

Why doesn’t adrenal fatigue exist?

Possibly because the term does illustrate how a person feels, many of us have been guilty of using the terminology of adrenal fatigue. We tend to imagine shrivelled up, sad looking little adrenals. This isn’t very scientific terminology, nor is it likely very accurate.

Why not?

First off, we have zero evidence that the adrenals can’t produce enough cortisol in this situation. What we do know is that cortisol levels can become chronically unbalanced. But the reason for this is likely to be associated with a disruption in the HPA axis (5) rather than adrenal glands being pooped out. Cortisol release from the adrenals is regulated by this axis which includes the hypothalamus, pituitary and adrenals. The hypothalamus and the pituitary are located in the brain. The brain is the main regulator of stress. First in how you perceive stress and then through the chemicals released by the brain structures (hypothalamus and pituitary) to get the adrenals to respond by secreting hormones such as cortisol.

Disruptions in the HPA axis have been studied in certain conditions such as chronic fatigue syndrome, PTSD and more (4,5). The response of the adrenals to the hypothalamus and pituitary actions may be blunted here. Low cortisol has been associated with certain conditions such as PTSD, fibromyalgia, asthma and chronic psychological stress. (1,3-5), but I see it daily in practice with individuals who have undergone chronic low grade stress for many years.

Are low cortisol levels preceded by high cortisol levels? Not necessarily. Which brings to question the stages of adrenal fatigue.

One of the most common symptoms of so-called adrenal fatigue is fatigue. Fatigue has multiple causes, which are important to rule out. Once we’ve fully investigated other causes for fatigue it would be prudent to investigate cortisol levels. We know from studying fatigue and chronic fatigue syndrome that cortisol levels correlate with energy levels (1,5). What is important to note here is that total cortisol levels do not correlate with fatigue (5), which highlights the importance of multiple measurements throughout the day (most easily and accurately done using salivary samples) to obtain a diurnal measurement of cortisol to get the full picture of your cortisol.

Does adrenal fatigue exist?

No, not in the way we are communicating, however low basal cortisol states do exist along with HPA axis disruption. A better name for what is thought of as adrenal fatigue, in my opinion, should be hypocortisolism (low cortisol). Also recognizing that this hypocortisol state may be a symptom of another disorder. It might all be semantics, but language is important especially when communicating with health professionals.

Dr. Meaghan McCollum, ND

Meaghan-130x150I am a strong advocate of integrated healthcare. To me this means bringing together all forms of healthcare from your healthcare team and communicating to help you reach your health goals. I work along side all types of practitioners and treatments.


  1. Heim C, Ehlert U, Hellhammer DH. The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrin (2000) 25:1-35.
  2. Vinson GP. The adrenal cortex and life. Molec and Cell Endocrine. (2009) 300:2-6.
  3. Kozlov AI, Kozlova MA. Cortisol as a marker of stress. Human Phys. (2014) 40:(2):224-236.
  4. Edwards LD, Heyman AH Swidan S. Hypocortisolism: an evidence based review. Integrative Medicine (2011). 10(4): 26-33.
  5. Powell DJH, Liossi C, Moss-Morris R, Scholtz W. Unstimulated cortisol secretory activity in everyday life and its relationship with fatigue and chronic fatigue syndrome: a systematic review and subset meta-analysis. (2013). Psychoneuroendocrin. 38:2405-2422.

Leave a Reply