Here is an explanation by Dr. Mariano on adrenal fatigue. I think it makes a lot of sense. For most of us, its not the adrenal glands themselves that have a problem, but rather stress (chronic or strong acute) that causes our HPA axis to be abnormal and result in lower secretions of cortisol.
"I have long ago stopped using the term "adrenal fatigue" because it is an inaccurate term. It is also an emotionally inflammatory term that can cause the physician risk to their medical license because it clashes with the existing definition of "adrenal insufficiency" and endocrinologists.
I have better names to use for the condition that do not clash with endocrinologists.
One problem is that though the term "adrenal fatigue" does describe the organ and symptom involved, it implies there is something structurally wrong with the organ. Unfortunately, this is inaccurate. There is nothing structurally wrong with the adrenal glands. And if there is something structurally wrong with the adrenal gland, the more accurate term is "adrenal insufficiency". I say "unfortunately" because "adrenal insufficiency" has criteria determined by endocrinologists. And the criteria for diagnosis are such, that almost all people with "adrenal fatigue" do not meet the criteria for "adrenal insufficiency".
Jefferies, in his book "The Safe Use of Cortisol", uses the term "MILD ADRENAL INSUFFICIENCY" to describe conditions that can fall under the term "adrenal fatigue". Thus his book is cited as supporting literature for the term "adrenal fatigue". Again, however, the endocrinologist criteria for adrenal insufficiency do not cover most of the people that Jefferies would say have "mild adrenal insufficiency". Thus, his use of the term can be criticized for also being inaccurate by endocrinologists. And, I have never heard of Jefferies (who died about 3 years ago) ever risking his reputation by using the term "adrenal fatigue". Since the term "mild adrenal insufficiency" can be much more easily supported - particularly since some of the criteria are arbitrary - one would be in better grounds using such a term to defend one's use of the treatments. However, one would also be forced to refer such a patient to an endocrinologist, who would then shoot down that diagnosis using his/her criteria. This would leave the patient in a grey area of practice where the diagnosis is not clear since two physicians disagree on the condition.
The second problem with the term "adrenal fatigue" is that it does not describe the actually cause of the condition. Since it does not describe the cause or pathophysiology, then one possible alternative and valid term to use is "ADRENAL FATIGUE SYNDROME". The addition of "syndrome" would be a more acceptable term since it implies no cause. Then it would be up to the physician to determine the list of symptoms and signs appropriate to the syndrome. And, of course, one criteria would be low output of cortisol - with "low" set at a level that is looser than defined by endocrinologists. This would be similar to the use of the term "SUBCLINICAL" when describing some conditions. Examples of "subclinical" include "subclinical hypothyroidism" as used in psychiatry to describe one contributing cause to bipolar disorder or major depressive disorder.
From my point of view, as a psychiatrist, the term "HYPOTHALAMIC-PITUITARY-ADRENAL AXIS DYSREGULATION" (HPAAD) is the most accurate and supported term in the literature that can be used instead of "adrenal fatigue".
In various mental illnesses (such as depression, bipolar disorder, anxiety disorders), the psychiatric literature is full of articles describing problems with cortisol production in mental illnesses. These conditions do not fit the criteria for adrenal insufficiency determined by endocrinologists. But clearly something is wrong with the hypothalamic-pituitary-adrenal system. And this problem is one of the central causes of mental illness.
In these conditions, the adrenal glands do change in size - enlargements or shrinkage. The adrenal glands do change in output - excessive or underproducing cortisol output. But there is nothing structurally wrong with the adrenal glands. It is in the regulation of adrenal function that something is wrong. And it is not due to a problem with ACTH production, primarily.
Some psychiatrists would argue that one problem with CRH production. CRH is both a hormone and a neurotransmitter produced by the brain and spinal cord. As a neurotransmitter, psychiatrists, in general, are more comfortable with the idea of using CRH problems as a cause, than if CRH was considered a hormone. However, from my point of view, there are other signals (neurotransmitters, hormones, cytokines, etc.) and metabolic problems that also contribute to HPAD. It is a complex condition.
This brings to mind, however, that the term "adrenal fatigue" is also more accurately described by the term "NON-ADRENAL ILLNESS AFFECTING ADRENAL FUNCTION" (NAIAAF) For example, in posttraumatic stress disorder, I frequently encounter cortisol levels under 5 ug/dL. These patients do not meet the criteria for adrenal insufficiency. But chronically, these patients do not have adequate output of cortisol in response to stress. The low output of cortisol in posttraumatic stress disorder is a repeated and valid finding in the medical literature. Clearly, it is dysregulation of the adrenal glands due to non-adrenal causes. Psychiatrists would point to problems with the sympathetic nervous system and CRH production as contributing factors. There is a psychiatric literature supporting the use of cortisol treatment for NAIAAF in such illnesses as major depressive disorder and posttraumatic stress disorder.
Endocrinologists would be much more comfortable with the term NAIAAF since this condition does not contradict their definition of adrenal insufficiency. Endocrinologists, for example, are comfortable with the term "NON-THYROID ILLNESS AFFECTING THYROID FUNCTION". These describe patients who have physical signs of hypothyroidism but do not have structural problems with the thyroid gland, where TSH is in the normal range. Again, often, these patients have mental illnesses. For example, in anorexia nervosa, patients often have problems with thyroid function due to metabolic problems. Yet they don't often meet the criteria for hypothyroidism as defined by endocrinologists.
Note that there is NO ICD-code for Adrenal Fatigue or Hypothalamic-Pituitary-Adrenal Dysregulation or Non-Adrenal Illlness Affecting Adrenal Function or Adrenal Fatigue Syndrome. THE ACTUAL DIAGNOSIS IS THE NON-ADRENAL ILLNESS INVOLVED. One cannot use an ICD code for adrenal illness since the definition of these illnesses are already used and defined by endocrinologists and would risk your reputation and medical license to use unless your patient actually can meet the endocrinologist criteria.
Since Adrenal Fatigue often describes a syndrome involving "fatigue", alternative medicine doctors often use the diagnosis, 780.79 Lethargy or Asthenia NOS or 780.71 Chronic Fatigue Syndrome. These are appropriate when the specific causes of the illness are unknown.
Adrenal Fatigue often describes a syndrome involving "stress" as a contributing factor to adrenal dysregulation. "Stress" is a mental health term and concept, since there is no stress if there is no brain. In this case, the appropriate psychiatric diagnosis can be used. For example, I may use 296.90 Mood Disorder NOS, 311 Depressive Disorder NOS, 300.00 Anxiety Disorder NOS, or any of the other appropriate psychiatric diagnoses. 300.5 Neurasthenia can also be used. Neurasthenia is a very common condition in response to stress, contributing to general fatigue.
In these conditions, the condition known as "Adrenal Fatigue" is considered a component of the actual illness involved.
In closing and summary, the term "adrenal fatigue" is a syndrome involving inadequate cortisol production in response to stress that does not meet the criteria for adrenal insufficiency. It involves dysregulation of the hypothalamic-pituitary-adrenal axis. From my point of view, contributing factors to dysregulation of the HPA Axis may include psychological/physical/environmental stress, nervous system problems, other endocrine problems, immune system problems, and metabolic-nutritional problems. The appropriate diagnosis is not "adrenal fatigue" but THE IDENTIFIED NON-ADRENAL ILLNESS INVOLVED. "Adrenal fatigue" is a subset of the symptoms and signs of this non-adrenal illness. A more appropriate term for "adrenal fatigue" is HYPOTHALAMIC-PITUITARY-ADRENAL AXIS DYSREGULATION or NON-ADRENAL ILLNESS AFFECTING ADRENAL FUNCTION. The treatment may include supportive treatment - such as treatment with Cortisol, etc. - at the physician's discretion and/or treatments aimed at the pathophysiology of the non-adrenal illness involved."