Many patients often ask me how the adrenal glands’ stress response affects the thyroid. Ultimately, the body’s response to stress has a dramatic effect on the thyroid. When undergoing stress, there are three chronological reactions by the adrenal glands. First, the acute phase, also known as the “alarm phase,” leads to elevated cortisol within the first 48 hours of stress. Then there is the “resistance phase” where the stress response lasts while cortisol levels stay elevated beyond 48 hours. The third phase is termed “exhaustion phase,” where the adrenals are so depleted by chronic stress that they can no longer sustain the body’s cortisol demands.
Each of these phases of the stress response play a role in thyroid metabolism. Both acute and chronic stress have a negative effect on the thyroid. In the acute alarm phase and the resistance phases of stress, cortisol levels are high. Studies show that persistently high cortisol inhibits the peripheral conversion of T4 to T3. Instead, the body shunts the production of T3 into an inactive metabolite called reverse T3. Reverse T3 is a commonly ignored marker that can produce symptoms of hypothyroidism because it does not induce metabolism within the body. In addition, hypothyroidism itself is a stress on the body. If the thyroid cannot produce enough thyroid hormones to sustain the body’s metabolism, then cortisol will need to pick up the slack. Thus, hypothyroidism itself leads to further cortisol elevation. This can cause a vicious cycle of low thyroid hormones and high cortisol, which will ultimately cause fatigue, weight gain, hyperglycemia and many other unwanted symptoms. This picture is also described as “wired and tired,” where patients describe themselves as extremely tired but cannot relax or sleep properly.
In the exhaustion phase of the chronic stress response, also known as “adrenal fatigue,” cortisol levels are depleted and chronically low. In this phase, the patient is overwhelmingly fatigued and “burnt out.” This phase also negatively affects the thyroid because thyroid hormones need a minimum amount of cortisol in order to work at the cellular level. Without cortisol, the thyroid hormones cannot properly bind their receptors and cannot perform metabolic functions. Even thyroid hormone medication cannot work properly without a certain amount of cortisol in the body. This can help explain why patients on thyroid medication sometimes do not notice improved symptoms when also under chronic stress.
Certainly, the thyroid and adrenal are intertwined, and both cortisol regulation and stress management are crucial for correcting hypothyroidism. In the acute alarm phase, it is important to relax the body, perform breathing exercises and supply the body with nervine botanicals to support the nervous system. This will help reduce the acute cortisol elevation and reduce reverse T3 production. During the resistance phase, it is still important to relax and use nervine botanicals, but therapy should also be specifically targeted for the adrenals to reduce cortisol production in the long term. This step can include the use of relaxing adaptogen botanicals and B vitamins to help us face and handle stress as it happens (editor: see here for definitions of nervines and adaptogens). In both of these phases, the patient should utilize stress management techniques, such as meditation, exercise, counseling, journaling, and hydrotherapy (editor: with water – see here), amongst others. In the burnout phase when cortisol is depleted, it is important to enhance cortisol production through the use of stimulating adrenal support and B vitamins. It is also crucial during this phase for the patient to take time to rejuvenate the body. Patients in this phase are often family caretakers who have neglected their own healing for many, many years. These patients can benefit greatly from counseling and other self-care modalities.
The standard thyroid screen for many doctors consists of a TSH and free T4 test. In order to further evaluate any abnormalities, an expanded panel may be warranted. An expanded thyroid evaluation will also look at free T3 and reverse T3. The free T3 is the most bioactive form of thyroid hormone within the body, and it is a useful measure of how your body’s conversion mechanism is working. Reverse T3 indicates faulty conversion potentially as a result of elevated cortisol, though nutritional deficiencies also lead to reverse T3 production. In addition to a thyroid panel, an adrenal workup is a standard evaluation by Naturopathic Doctors for a patient with hypothyroidism. A simple salivary cortisol test, taken 4 times throughout the day, can give useful information about how stress may be affecting the thyroid. With these thorough workups, a personally tailored protocol can be developed for your specific phase of stress. However, even without these lab tests, every patient with hypothyroidism should try to incorporate stress management into daily life to enhance the functioning of the thyroid gland.
Friedman, Michaël. Fundamentals of Naturopathic Endocrinology: Complementary and Alternative Medicine Guide. Toronto, ON: CCNM, 2005. Print.
Walter, K.N., Corwin, E. J., Ulbrecht, J., et al. Elevated thyroid stimulating hormone is associated with elevated cortisol in healthy young men and women. Thyr Res., 5(13), 2012.
De Nayer, P., Dozin, B., Vandeput, Y., et al. Altered interaction between triiodothyronine and its nuclear receptor s in absence of cortisol: a proposed mechanism for increased thyrotropin secretion in corticosteroid deficiency states. Eur J Clin Invest., 17(2), 1987.
Hackney, A. C., Kallman, A., Hosick, K. P., et al. Thyroid hormone responses to intensive interval training versus steady-state endurance exercise sessions. Hormones. 11(1), 2012.