Thyroid Dysfunction and the HPA Axis

At Rejuvenate MKE, one of our most common consult requests is for hypothyroidism. Women and men alike contact us for evaluation of hypothyroidism symptoms: fatigue, weight gain, and hair loss, to name a few. In many cases, these patients have already spoken to their primary care provider and have had lab testing performed to evaluate their thyroid, and, oftentimes, these tests come back completely normal. Understandably, this leaves patients frustrated and still suffering from their symptoms.

In our clinic, we utilize functional medicine to help treat these symptoms; in reality, even if your traditional blood tests come back normal, you still may have underlying thyroid dysfunction, and that’s because of the relationship between the thyroid gland and the HPA axis. In this article, we explore this relationship and why you may be having symptoms of thyroid dysfunction, even if traditional bloodwork says otherwise.

The HPA axis is a complex network of interactions between the hypothalamus, pituitary gland, and adrenal glands that plays a crucial role in regulating the body’s stress response. When the body experiences stress, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then signals the adrenal glands to release cortisol, which is a primary stress hormone.

Chronic stress can lead to dysregulation of the HPA axis, causing an overproduction or underproduction of cortisol. This dysregulation can, in turn, disrupt the balance of other hormones in the body, including thyroid hormones.

When cortisol levels are consistently high, it can lead to decreased thyroid function by suppressing the production of thyroid-stimulating hormone (TSH) in the pituitary gland. TSH stimulates the thyroid gland to produce and release thyroid hormones, which play a critical role in regulating metabolism, growth, and development.

In addition, cortisol can interfere with the conversion of thyroid hormone T4 to T3, the active form of thyroid hormone, in the liver and other tissues. This can lead to decreased levels of T3, which can cause symptoms of hypothyroidism, such as fatigue, weight gain, and cold intolerance.

On the other hand, when cortisol levels are consistently low, it can lead to increased TSH levels and overstimulation of the thyroid gland, which can cause hyperthyroidism.

Thyroid dysfunction can also lead to dysregulation of the HPA axis. For example, hypothyroidism can lead to an increase in CRH and cortisol levels, while hyperthyroidism can lead to a decrease in CRH and cortisol levels.

In summary, the HPA axis plays a crucial role in regulating thyroid function, and dysregulation of the HPA axis can contribute to the development of thyroid dysfunction. Chronic stress, which can lead to dysregulation of the HPA axis, should be addressed as a potential contributor to thyroid dysfunction. Additionally, thyroid function should be evaluated in patients with HPA axis dysregulation to ensure proper diagnosis and treatment.

Note: The information provided in this article is for educational purposes only and should not be considered as medical advice. Consult with a qualified professional for personalized recommendations and guidance based on your specific situation.