Four tiny organs produce hormones that regulate everything from our blood pressure and libido to our metabolism and stress response. That’s an enormous job!
These organs are…
The hypothalamus, pituitary gland, and adrenal glands.
As with every other part of the body, the adrenal glands do not operate independently. Rather, they are part of a complex system called the hypothalamic-pituitary-adrenal loop (a.k.a. HPA axis). The central nervous system and endocrine system connect via this HPA axis, working together to regulate stress response and hormone balance.
H = Hypothalamus
This almond-sized gland is the link between the endocrine and nervous systems. It sends messages from the brain to the pituitary gland and adrenals. By maintaining body temperature, energy levels, and circadian rhythm, the hypothalamus essentially maintains the body’s homeostasis (source).
It is responsible for the production of hormones like:
- Gonadotropin-releasing hormone — ensures normal function of testes and ovaries
- Oxytocin — involved in orgasm, the ability to trust, body temperature, sleep cycles, and the release of breast milk
- Thyrotropin-releasing hormone — triggers the release of thyroid stimulating hormone (TSH), which stimulates release of thyroid hormones, which regulate metabolism, energy, and growth and development
- Corticotropin-releasing hormone (CRH) — stimulates the release of adrenocorticotropic hormone (ACTH), which stimulates release of adrenal hormones, which regulate stress response
P = Pituitary Gland
The pituitary gland — a pea-sized organ — sits at the base of the brain, not surprisingly, near the hypothalamus. It is often called the “master gland” because its hormones control the thyroid, adrenals, ovaries, and testes.
It produces hormones like:
- Growth hormone — essential in early years for healthy body composition and growth in children. In adults, it aids healthy bone and muscle mass and affects fat distribution.
- Adrenocorticotropic hormone (ACTH) — stimulates the adrenal glands to produce hormones
- Thyroid-stimulating hormone (TSH) — stimulates the thyroid gland to produce hormones
- Prolactin — stimulates breast milk production
A = Adrenal Glands
These walnut-sized glands, sitting atop each kidney, control the “fight or flight” response and other chemical reactions throughout the body. Each gland is made up of two parts: the adrenal cortex and the adrenal medulla.
The adrenal cortex, the outer part of the gland, produces hormones like:
- Hydrocortisone, a.k.a. cortisol — is often called the stress hormone because it helps our bodies respond to stress (our “fight or flight” response). Additionally, cortisol helps regulate metabolism, controls the sleep/wake cycle, and suppresses inflammation.
- Corticosterone — works with hydrocortisone to regulate immune response and suppress inflammatory reactions.
- Aldosterone — regulates blood pressure by maintaining the balance of salt and water in our blood.
- DHEA and other sex hormones — in men, are converted into testosterone by the testes. In women, the adrenals are the primary source of these androgens, so their role is very significant.
The inner part of the adrenal glands, the adrenal medulla, produces “non-essential” hormones. That is, you don’t need these hormones to survive, but they are still very important. Among other things, these hormones are neurotransmitters, and they prepare the body to respond quickly in moments of danger or trauma. These hormones are:
- Adrenaline, a.k.a. epinephrine — helps regulate the body’s “fight or flight” response (how the body responds to stress).
- Noradrenaline, a.k.a. norepinephrine — works with adrenaline during the stress response. It also causes vasoconstriction which results in raised blood pressure.
How The HPA Axis Works
Here is how the HPA axis works… The most important thing to understand is that “adrenal fatigue” involves more than just the adrenal glands. 🙂
- Stressor is present (whether bear or bill collector).
- The hypothalamus secretes CRH (corticotropin-releasing hormone) which tells the pituitary gland to produce ACTH (adrenocorticotropic hormone).
- ACTH prompts the adrenals to make cortisol, adrenaline, and noradrenaline.
- Cortisol raises blood glucose and slows digestion, while adrenaline and noradrenaline increase the heart rate and blood pressure. These actions prepare the body to fight or flee the stressor.
- This cycle continues until your body has enough hormones to deal with the stressor.
- Once cortisol levels begin to decrease, the stress response stops, the body calms down, and hormone levels to return to normal.
These interactions continue until your hormones reach the levels that your body needs, and then a series of chemical reactions begins to switch them off. For example, the cortisol released by the adrenals actually inhibits the hypothalamus and pituitary (so they stop sending signals to produce more cortisol!). This is just one of the automatic switches that we call negative feedback loops, and these loops are one reason why the HPA axis is so extraordinary. (Source.)
So, what happens when there’s an interruption of this flow?
Adrenal Fatigue Or HPA Axis Dysfunction?
The term Adrenal Fatigue was first coined back in the 1990s by Dr James Wilson. But it’s not really a very descriptive name for a syndrome like this. You might hear doctors taking about HPA Axis Dysregulation, or HPA-D, which is often used now. They mean the same thing.
The adrenal glands don’t really get ‘tired’ in the way that you might expect. What happens is that, after a period of chronic stress, your body starts to run out of the hormone precursor material that it uses to make certain hormones. As this continues, it becomes more and more difficult for your body to produce the required levels of stress hormones, sex hormones, and other hormones and neurotransmitters. That’s when the ‘fatigue’ starts to kick in, and that’s when you need to offer your body some extra support. (Source.)
Notice the words “chronic stress”? Anything that causes prolonged stress, and subsequently, the prolonged need for and release of stress hormones from the HPA axis, can and does cause adrenal fatigue. However, HPA axis dysfunction, which is the same thing as adrenal fatigue, is the better term. After all, stress affects not only the adrenal glands, but the entire loop.
Furthermore, single, stressful events can and do cause trauma, too. This trauma can put the body in chronic stress mode and cause HPA axis dysfunction as well.
When chronic stress occurs in an individual, the HPA axis continues to release hormones on an accelerated basis. But after time, the overproduction of these hormones leaves the glands of the HPA axis desensitized and they stop recognizing signals to stop producing hormones. The negative feedback loop is no longer functioning as it should and HPA axis dysfunction becomes the norm.
The idea of adrenal fatigue has become popular in natural and alternative health world in recent years. But while many alternative practitioners are focusing on the adrenal glands being fatigued as a result of chronic stress, that is only one part of the equation. It is actually the dysfunction of the entire HPA axis that is creating the symptoms, not simply a dysfunction in the adrenal glands alone. It is the dysfunction of the feedback loop of the HPA axis that ultimately creates the symptoms that people now associate with adrenal fatigue. (Source.)
Symptoms Of HPA Axis Dysfunction
This chronic stress and constant stress hormone production wears on the body. Over time, it can cause a myriad of symptoms, such as…
- weight gain, especially in the mid-section
- brain fog
- thyroid dysfunction
- depression and/or anxiety
- hypoglycemia and other blood sugar problems
- all-day fatigue, particularly in the morning and mid-afternoon
- cravings for salt or salty foods
- depressed immune system/recurrent illnesses or infections
- dizziness when standing (orthostatic hypotension)
- blood pressure issues
- rise in allergies — food, chemical, or environmental
- low libido
- poor muscle tone or loss of muscle mass
- dry skin
- slow wound healing
- inability to concentrate and focus
- memory problems — can’t remember why you walked into a room or where your car keys are
- cold hands and feet
Are you familiar with the symptoms of adrenal fatigue? These sound pretty similar, don’t they?
“I Feel Awful. Does It Really Matter What It’s Called?”
Maybe you have many or most of the symptoms on the above list. Furthermore, maybe you’ve done your research and have concluded that you actually do have adrenal fatigue.
Yet now I’m telling you it’s not adrenal fatigue. Instead, it’s HPA axis dysfunction.
You don’t really care what it’s called; you just want to feel better!
In this case, terms matter. Here’s why…
First, let’s say you visit your run-of-the-mill, allopathic physician. You describe most of the symptoms above, and ask him about adrenal fatigue. He may look at you funny. You see, the medical community does not recognize the term “adrenal fatigue” as an actual thing. Even many natural-minded physicians don’t recognize it.
The adrenal fatigue concept is not supported by peer-reviewed, scientific evidence, nor does it align with our current understanding of HPA axis physiology. If you search for “adrenal fatigue” in PubMed, you’ll find only 12 results … In contrast, if you search for “hypothalamic pituitary adrenal axis” in PubMed, you’ll see more than 19,000 search results, featuring studies linking changes in the HPA axis to everything from Alzheimer’s to obesity. (Source.)
Quite honestly, you may not find an allopathic doctor who recognizes HPA axis dysfunction (HPA-D) either. This is why we always advise working with a qualified functional medicine practitioner or naturopath.
Second, although the adrenals produce cortisol, the brain and central nervous system primarily govern its production. While cortisol testing, via spit or urine, may help identify part of the problem, it rarely identifies the full problem.
Free cortisol, measured in the blood or urine, is not representative of total cortisol production, which is often normal or even elevated but doesn’t show in tests (source).
Trust How You Feel, Not The Numbers
When it comes to hormones, always trust how you feel… not the numbers. And find a practitioner who will do the same!
Testing specific hormones is useful, but it is rarely the full picture. So often, hormones aren’t tested together to give a more complete picture.
For instance, a diurnal salivary test captures free cortisol in the saliva over a 24-hour period. If your numbers are anywhere in the “normal” range, and your doctor trusts numbers more than how you feel, she may say that your anxiety, hypoglycemia, insomnia, weight gain, and allergies aren’t HPA axis-related. Worse, she may say that it’s all in your head!
However, if your numbers are within the “normal” range, and you have a practitioner who trusts how you feel, she will continue to help you heal and support your HPA axis through diet, supplements, and lifestyle changes.
Finally, HPA axis dysfunction is not an easy thing to heal, but it is possible. Over the coming months, I plan to share more of my own story. I’ll also share how you can nourish, support, and heal HPA axis dysfunction using essential oils, food, lifestyle changes, and supplements.
More Adrenal Health Related Articles:
- What Is Rhodiola? (the anti-fatigue, anti-stress adaptogen!)
- Top 5 Essential Oils For Adrenal Support
- 5 Foods That Are Wrecking Your HPA Axis
- 5 Foods That Nourish The HPA Axis
- 5 Reasons to Heal Your Gut
Have you heard of HPA axis dysfunction? Were you calling it adrenal fatigue? Can you share how HPA-D makes you feel? What are you doing to support your body?
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Yes this describes me. I am so frustrated by the amount of money I have spent on natural doctors, supplements, etc and have gotten no better. I am so excited to hear your findings and recommendations of what to do.
Kathy E says
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Dr. D’Adamo’s early publication stayed on the NY Times best seller list for 7 years runnung. Never give up. Check it out.
I too cannot wait to hear more! I have spent an ungodly amount of money with a naturopath for my hormone imbalance/adrenal fatigue. I finally after 2 yrs got to goal weight through a VERY strict limited eating plan and supplements but then it stopped working and I slowly started gaining weight again. My dr just said Hmmm I don’t know you should probably do a cleanse for 8wks and see where you are. Needless to say I lost complete faith in him and trying to figure it out on my own.
Yes Ive been calling it hpa axis dysfunction for yrs. Hasnt gotten me anywhere lol
Robbie Lieske says
I’m there with Stacy, too! I’m 71 and I’m so discouraged by all the money I’ve spent, all the natural doctors I’ve seen,all the expensive tests I’ve had done, all the supplements I’m taking and have taken, blogs and books I’ve read (and purchased), changes I’ve made, and the weight still won’t come off, and I don’t feel any better. I’m looking forward to seeing what you have to say.
Did she ever get back to you??
Cheryl Benoit says
Me too, lots of symptoms on the list . Conventional medicine doc actually laughed when I asked her about Adrenal Fatigue. ( I changed Primary docs after one visit with her ! ) I really like the fact that you say here that numbers don’t always give an accurate picture , how true . In fact, the medical society changes the numbers , such as the recent change in Blood Pressure numbers ! So one day you have “normal” blood pressure with one number, the next day after it’s been changed, you now have “high” blood pressure ! They do the best they can , I am thankful for traditional MD’s when I have an acute problem . One symptom that I saw listed here is craving for salt and oh wow, that has been me for quite a while. I look forward to hearing more from you , and all the other people who comment. Thanks so much : )
Yes this describes me to a tee! I only have one adrenal gland as I had a growth on the other one and they removed it in 2002. Does this change things? I have trouble finding information or support groups etc. for this problem. Because my blood pressure returned to normal immediately after surgery they said I would be fine. Some of symptoms I have always had others are recent. Can you suggest any avenues I should look into?
Lindsey Dietz says
Linda, having a missing adrenal gland probably is a contributing factor to your issues. I would suggest working with a naturopath or functional medicine provider to help with your unique situation. Hugs!
Becky B says
This is a beautiful description of a very complex system! Nicely done! Thank you
Lindsey Dietz says
You’re so welcome, Becky! Our goal is to make complicated health information easy for everyone to understand!
I plan to follow along with your information, too many of these symptoms are exactly what I’m feeling, but cant really afford to spend money on tests that wont be able to pinpoint the problem-or, at least, isnt likely to. I am getting better at listening to what my body has to tell me and trying to respond to that.
Lindsey Dietz says
Listening to your body is the BEST thing you can do, Janie! Hugs!
Deb M. says
Looking forward to hearing more about this! Never heard it called this before…but I can see it’s not just the adrenals. Interesting! Thanks for sharing this with us!!
Lindsey Dietz says
You’re not alone, Deb! Many people have never heard of HPA axis dysfunction! Hopefully, you can learn more about it in the coming months!
Yes this describes me to a T! I’ve never heard it called that before, but it makes a lot of sense. My Clinical Nutritionist said she does not like to give names to symptoms, because then people let it become part of their personality. Wow, I thought that was wise!
I’ve also spent a small fortune in the last number of years. I’m getting better, but it is extremely slow and very frustrating to gain any ground! I’ve got more going on than just this. I see a Clinical Nutritionist. She’s very good at what she does. She looks at numbers (once in awhile) but she relies more on how I feel and Kinesiology. I did the 23andme saliva test and she took the raw data and plugged it into Dr. Ben Lynch’s software. We learned a lot through that. Apparently, your epigenetics (expression of your genes) can be affected by certain things that aren’t normal for everyone else. The HPA Diagram (above, in this article) is a wonderful flow chart of how the HPA works. In epigeniology (is that a word?) Dr. Ben Lynch’s software shows these types of flow charts, but it shows what can spend up healing for you or slow it down. I was taking supplements that maybe had 5 herbs in it. I tested well with kinesiology, but I wouldn’t do well on it. Now we know why. Some of the herbs were so good for me that it overpowered the testing of the ones that didn’t work in that supplement. But it, nonetheless, slowed my healing.
There is soooooo much we don’t understand. There are so many health practitioners that don’t keep learning, studying, researching for themselves. I’m always trying to learn more and this article is something that really helped! Thank you Wardee & Lindsey! I would encourage people to find a health practitioner that LISTENS to you! If they don’t, keep searching for one that will.
There are several quotes that if people heard them, remembered them and used them as a guideline for their lives, it would really help them:
“Let thy food be thy medicine and thy medicine be thy food.” ~ Hippocrates (the father of modern medicine)
““The doctor of the future will give no medication, but will interest his patients in the care of the human frame, diet and in the cause and prevention of disease.” ~ Thomas A. Edison
OK, that’s my two cents worth… I hope this might help someone…
Lindsey Dietz says
We hope we can provide you with information in the coming months that will help you get better, Sandi! Hugs!
I have an adrenal tumor they have decided to just “watch.” Removal is not an option at this point. I have many symptoms that come and go. I hair loss a symptom of this HPA axis dysfunction? I have lost about half the hair I used to have in less than a year. I have also been diagnosed with type 2 diabetes, but metformin and watching my diet has helped lower my A1C somewhat. All this has happened within a year of discovering this tumor. The surgeon is convinced it is a benign tumor and not a pheochromocytoma or cancer. I had a very elevated norepinephrine level last spring, and after being put on a different blood pressure med, it has returned to normal as of last fall. It will be tested again this spring.
Ajene Gailliard says
WOW!!! This is sooooo affirming. I have spent so many years, so much money, time and energy looking for answers to my health issues, only to be told that my labs where “within normal range.” I have been misdiagnosed with PCOS and suffered for years with almost all of these symptoms and still have not found relief. I had a functional doctor, who totally dismissed what I have been going through and told me that I “was a hard case.” It has been difficult to hold on to any hope. I have most recently been told I have several food allergies and I’ve was diagnosed with Celiac disease, despite “normal” test scores and no antibodies last month.
Giving up gluten and these allergens has not made a difference and I am still suffering. I struggle with weight and no matter how well I eat, the scale will not budge and my symptoms are the worst they’ve ever been.
I am looking forward to learning more and finding healing and relief. I will not give up on the hope that one day, I will have the health I have been praying for. As a woman of faith, I do the practical things to benefit my health, but I also stand on the promises of God that I can have life and life more abundantly. I trust that the Lord will heal my body and I will testify of His miracle working power, and I pray the same for all of you.
May God’s Blessings Be Upon You,
Lindsey Dietz says
I’m so sorry for your struggles, Ajene! <3 I hope the information I share in future posts is super helpful to you. Hugs!
Joan Tendler says
Thanks for your very clear article. I was diagnosed with adrenal fatigue by Dr. Wilson nine years ago, and he told me that it was the worst case he ever saw-not very hopeful! In fact, a year later I had a major back problem and became bed-ridden for a few years. I had been a “Mediterranean” vegetarian for 35 years, which I found out explained much of my problem. So, I discovered Weston A. Price, and gradually changed my diet until, for the last year, I have been eating only the foods of my Northern European ancestors, like pork, chicken or pea soup, raw cheese, and sourdough rye bread. This diet avoids the problem of salicylates, which are a major part of adrenal fatigue, plus pork is the top source of B1, our energy source. I now work out for an hour a day in the gym-no supplements, sugar, or caffeine, needed. So, there is recovery from adrenal fatigue!
Lindsey Dietz says
This is wonderful to hear, Joan! I hope others find the same healing!
Please do follow up with your proven methods and suggestions. I’m a work in progress and don’t wish to spend years and money with no results! I’m in a mission to heal before it gets out of hand!
Lindsey Dietz says
Marianne, several follow-up articles have been written! 🙂 Topics include essential oils for adrenal support and foods that are helping/hurting the HPA axis. Type “hpa axis” in the search bar above and you’ll find what you’re looking for!
Is there a part two to this article?
Lindsey Dietz says
Hi Sara! Not necessarily a “part 2”, but we do have a few more posts related to the HPA axis on the blog! Type “hpa axis” into the search bar at the top, and you’ll find them! Let me know if I can help again! 🙂
I had a severe adrenal crash this year after being a caregiver for 6 months to my brother during his battle with stage 5 squamous cell carcinoma of the tongue. The prednisone that I had been prescribed for my depleted adrenals just wasn’t working any more. I’ve been battling adrenal fatigue for the last 5 or more years. With my meds no longer working, and flank pain and dark urine even when awake and drinking lots of fluids and chest pain, I was left to re-evaluate the common thought on glandulars and I decided to jump in with both feet. I’m glad I did. I’m getting my life back. I began taking brain glandular, kidney, adrenal, heart, stomach, thymus as well as the thyroid glandulars that I’d been taking previously. I then added pituitary and hypothalamus as I realized that directly supporting the H-P-A axis would be beneficial. I now wake up without pain in my feet every morning. I have energy — not much — but a tad more. I had been taking the glandulars 3 times a day and I’m down to twice a day. I just don’t need them in the evening. I’m also taking supplements and multi mineral to support my healing.
I saw fast improvements when I was able to locate a source of hypothalamus glandular (and not just a brain glandular).
Libby could you be more specific as to which pituitary and hypothalamus glandular/s you added? I presently take only thyroid glandular. Thanks and bestwished to your continued success.
Wendy Gardner says
The overlap between menopause and HPA axis dysfunction is huge!
I wonder if I’ve been blaming meno when in fact its HPA that’s out…