Tagged with 'Thyroid '

Could stress be affecting my thyroid?

The stress response is meant to improve your chances of surviving a physical threat to your safety temporarily, but prolonged, frequent or extreme stress can have devastating effects on your health. Arguably, we are more stressed today than ever before in human history. As a result, stress accounts for 75 – 90 % of all primary care visits in the US and chronic stress is now acknowledged as a key driver behind most of our modern health complaints, both psychological and physical. Stress is also considered to be the number one reason why people eat poorly and quit healthy lifestyles programs. The Stress–Illness connection It is fair to say that nearly all illness is stress-related: It’s either caused by stress, aggravated by stress or causes stress. While the mechanisms by which stress contributes to the disease process remains to be fully understood, research shows that chronic stress can disrupt the intricate connection between our brain and our endocrine system, known as the hypothalamic-pituitary-adrenal (HPA) axis system. During stressful periods, the hypothalamus secretes corticotropin-releasing factor (CRF), a peptide hormone and neurotransmitter whose role is to stimulate the pituitary synthesis of adrenocorticotropic hormone (ACTH). ACTH then travels through the bloodstream to reach the adrenal glands and causes them to release the stress hormone cortisol. Researchers have demonstrated that both acute and chronic stress contribute to high levels of cortisol. This stress hormone is involved in multiple bodily functions and its increased secretion during the ‘fight-or-flight’ response is necessary to support the breaking down and the use of fatty acids and proteins needed for energy production. However, a chronically elevated cortisol level has been associated with several health challenges, including thyroid dysfunction. Thyroid dysfunction In conventional medicine, thyroid disease is treated as a random malfunction of the thyroid gland. In fact, experience in clinical practice demonstrates that poor thyroid function is often related to other issues, such as chronic stress, hormonal imbalance, toxicity, digestion and nutritional deficiencies. So if you have been undergoing prolonged periods of stress, stress hormones may have been inhibiting your thyroid function for years! It is actually quite common to see patients experiencing thyroid dysfunction even when their thyroid lab tests appear “within normal limits”. The prevalence of ‘subclinical hypothyroidism’ is related to the fact that the thyroid stimulating hormone (TSH) value, the hormone routinely checked to diagnose hypothyroidism, is only a part of the story. Symptoms, lifestyle, diet, physical findings and health history are also important considerations when diagnosing thyroid health. For example, chronically overtaxed adrenals glands can lead to hypothyroidism, as the thyroid may decrease its hormonal activity in an attempt to reverse adrenal overdrive. Indeed, we may think of the thyroid and adrenals glands as sentinels of the endocrine system. They operate as sensors responding to the constant variations occurring within our body, and transmitting that flow of information back and forth between the body and the brain. Since both the adrenal and the thyroid loops communicate with the hypothalamus and the pituitary glands in our brain, and the hormones produced along these two axes are closely associated, the risk of dysregulation along one axis is much higher when the other one is out of balance. Chronic stress can affect thyroid function in other ways. High levels of cortisol are known to inhibit the production of TSH, the hormone that stimulates the thyroid gland to produce its hormones. An elevated cortisol level can also impair the conversion of the thyroid hormone thyroxine (T4) to triiodothyronine (T3), its active form. Moreover, the amino acid tyrosine which is needed for thyroid hormone production is also used in the making of the stress hormones adrenaline and noradrenaline. We can easily understand that the chronic over activation of the HPA axis will eventually result in a shortage of raw material for thyroid hormone production! It is also important to understand that when we are facing a perceived stressor, our whole system gets into the ‘fight-or-flight’ mode at the expense of other bodily functions such as our digestive process. Under chronic stress, the liver has a decreased ability to metabolize excess estrogens circulating in the blood, which in turn increases the level of thyroid binding globulin (TBG), the protein that transports thyroid hormones. In order for thyroid hormones to exert their physiological effect, they must activate receptors found on the cells. Thyroid hormones bound to TBG are inactive; they must be cleaved and become ‘free’ to activate cellular receptors. To make matters worse, studies have shown that inflammatory cytokines produced during the stress response suppres ...