Hypothyroidism can be primary or secondary. If it is primary, it should respond well to thyroid replacement. If low thyroid symptoms (fatigue, weight gain, dry skin and hair, constipation, low body temp, depression, hair loss, etc.) continue despite treatment, then it is secondary and one must look at the underlying factors that may be contributing. If that underlying cause is adrenal fatigue, then treatment of hypothyroidism without adrenal support is not only ineffective, it can be highly counterproductive.
When the adrenal glands are not functioning properly, it is difficult for them to handle the naturally occurring stress that is associated with normal body functions and energy production, so it will downregulate the production of energy and all metabolic functions including the thyroid in order to conserve energy and get some well-needed rest, thus leading to chronic fatigue and low thyroid function.
Dr. Michael Lam, an adrenal expert, explains that when the thyroid is downregulated, then production of T4 and T3 (thyroid hormones) is reduced, but TBG (thyroid-binding globulin) will increase, which results in less free T4 and free T3 if measured in the blood. Some T4 is also directed towards making the inactive rT3 (reverse T3), which works as a braking system to oppose T3 functions, both of which can persist long after the stressful situation has ended. rT3 can also inhibit the conversion of T4 into T3 and perpetuate the production of rT3. If the level of rT3 is higher than the T3, then it can result in what is called rT3 dominance, whereby symptoms of hypothyroidism are experienced despite sufficient levels of T3 and T4 being present in circulation. When this occurs, then standard lab tests that measure T4 and T3 may be normal despite hypothyroid symptoms and low body temperature. On the other hand, free T4 and free T3 may be low on lab tests while TSH is normal or high. Administering thyroid medication may cause lab tests to normalize, but the individual will continue to have deterioration in health and low body temperature.
This whole series of events is directed by the adrenal glands to intentionally slow things down in the body so that it can rest and ensure survival. Therefore, under these circumstances, thyroid replacement with T4 or T3, without first addressing the adrenal glands can lead to more deterioration in the adrenal glands and the thyroid. The body wants to slow down and rest, but the medication which increases metabolic functions and energy production will speed things up. Increasing T4 and T3, directly opposes the goal of the adrenal glands attempts to do what is best for the body. You are essentially trying to jump-start the system while the system is applying the brakes. Dr. Lam states it is “analogous to pouring oil onto a fire.” The weak adrenal glands will not be able to handle the stress associated with these functions, that is why they downregulated the system in the first place. So forcing them to do so, will only deplete them even further. This can result in someone who has a mild case of adrenal fatigue to advance to the more serious exhausted phase. For someone who is already in an advanced stage, it can lead to a severe adrenal crash and impairment in the ability to function.
Under these circumstances, thyroid medication may provide some relief in fatigue and other symptoms initially, but it doesn’t last long. As the adrenal glands become more burdened and weakened from the medication, then they downregulate the system even more and symptoms get worse than they were before. At this point, many practitioners then increase medication or switch to a different one, which once again may provide some initial relief, but ultimately cause more weakening of the adrenals and worsening of both conditions (adrenals and thyroid). A vicious cycle ensues, whereby the adrenal glands continually reduce the body’s response to the medication leading to a need for more medication and exacerbation of symptoms.
Additionally, the adrenal glands are one of the primary players in the HPA axis, and when they are not functioning up to par, then pituitary and hypothalamic action is depressed. Both the pituitary and hypothalamus are needed for thyroid hormone production. Stressed adrenals also inhibit the conversion of T4 into its active T3 form and decrease thyroid receptor sensitivity, meaning cells lose their sensitivity towards thyroid hormone in a similar manner as insulin resistance. Other functions of the pituitary and the hypothalamus may become impaired as well like body temperature, appetite, thirst, sexual arousal, sleep, hormone production, fertility, metabolism, etc. When the adrenal glands become impaired for an extended period of time, then cortisol and DHEA levels will begin to drop out and both cortisol and DHEA are needed in modulating thyroid function.
Poor adrenal function can be caused by a variety of factors, which are discussed in more detail on the following page, but two of the most common are chronic Candida overgrowth or SIBO. Both of these conditions, when present for a long time, can become a huge burden on the adrenals glands as the body struggles to deal with the stress they generate. Additionally, when liver function gets compromised from toxins released by Candida or bacteria, then it can’t convert T4 to T3 sufficiently, contributing to more thyroid dysfunction. Candida toxins can also mimic thyroxin (a primary thyroid hormone,) thus inhibiting the proper function of the thyroid gland in this manner as well. Furthermore, Candida has a protein that can bind with corticosteroids (hormones produced by adrenals) making them unavailable for use by the body and it can impair human hormone signals of all kinds.
Thyroid hormones are needed for every cell in the body. When the thyroid slows down, all other organs and systems decelerate as well, including motility. Contraction of muscles that move food and stool throughout the gastrointestinal tract are weakened, which leads to slow transit time and constipation. Impaired motility then creates an environment that encourages overgrowth of Candida and SIBO. Therefore, overgrowth of Candida or bacteria perpetuates low thyroid and adrenal function, which then perpetuates overgrowth of Candida or bacteria. Treatment must focus on not only eliminating the overgrowth of yeast or bacteria but on supporting the adrenal glands as well. You can learn more about the basics of recovery for the adrenal glands here and Candida here.
You can assess the health of your adrenal glands, how they are being affected by stress, and where you are on the spectrum in regard to the severity with a cortisol saliva test. This information can then be used to guide your healing plan and monitor your progress as you go along.
On the flip side, thyroid function can be affected by a variety of other factors, which you can read about on my hypothyroidism page, like insufficient levels of iodine, selenium, or tyrosine; pesticide or herbicide exposure; halides; other problems with the pituitary or hypothalamus; neurotransmitter depletion; insulin resistance; heavy metals; and genetic mutations. So, if the thyroid is inhibited from some other source, this can lead to constipation, cravings for sugar and carbs, and other issues that could then contribute to the overgrowth of Candida or SIBO as well, which would then lead to more impairment of adrenal and thyroid function.
If you have not responded to thyroid treatment, or have observed the aforementioned events, then you should consider the possibility that adrenal fatigue is at the root of your thyroid problem. When the adrenal glands are supported and begin to get stronger again, they will stop downregulating the system, and then hypothyroidism symptoms often just improve naturally by themselves, as the thyroid is permitted to restore normal functions. Additionally, as adrenal function improves, then medication may not be needed at all anymore or it may need to be reduced. According to Dr. Lam, a classic picture of someone who has low thyroid caused by poor adrenal function consists of high levels of thyroid-binding globulin (TBG), low free T4, low free T3, high TSH, slow ankle reflex, and low body temperature.
Dr. John T. Trowbridge. The Yeast Syndrome. Bantam (October 1, 1986)