In this article:
We all experience stress in our daily lives. While stress usually gets a bad rap, it’s sometimes advantageous. For example, an acute stress response can help us escape a dangerous situation or give us the added last-minute boost needed to meet a looming deadline.
Some people experience chronic stress that lasts weeks, months, or even years. Chronic stress can result from our daily routines, sudden or difficult life changes, or emotional trauma. In some cases, recovery from emotional trauma is complex and can develop into a chronic condition known as Post Traumatic Stress Disorder, or PTSD.
In this article, we’ll look at how trauma, stress, and PTSD can impact your health, specifically your thyroid function.
Understanding the relationship of stress to thyroid disease requires a look at the physiological processes underlying stress. First, your brain and body respond to stress by releasing hormones. These hormones make you alert and prepare you for action. You may have heard this referred to as the “fight or flight” response.
In fight or flight mode, your body responds to a perceived and imminent danger. This causes a rapid release of hormones to prepare you to fight or run away. Because of this, your blood pressure, heart rate, and blood sugar increase. You may experience physical symptoms, including chest pain, a headache, dizziness, shaking, muscle tension, a clenched jaw, and a stomach ache. Once the stress-inducing event is over, your blood pressure and heart rate will return to normal, and symptoms will subside.
In contrast, when you are experiencing chronic stress, your body remains in “fight or flight” mode, and stays in this heightened state, rather than returning to normal. The physical symptoms of chronic stress include chronic aches and pains, difficulty sleeping, fatigue, brain fog, appetite changes, and emotional and social withdrawal, among others.
Chronic stress puts you at risk for developing serious health problems, including:
- An increased risk of autoimmune disease
- A suppressed immune system, and an inability to fight infections
- Endocrine disorders such as diabetes
- Gastrointestinal complications, including changes in appetite or bowel movements
- Cognitive issues and memory problems
- Heart disease
While chronic stress is bad for your health, how does it affect your thyroid function? The answer lies within your hypothalamic-pituitary-adrenal axis, also known as the HPA axis.
The “stress response” starts in the brain, specifically in the hypothalamus, with the release of corticotropin-releasing hormone (CRH). This hormone travels to another part of your brain called the pituitary gland. Here, CRH tells the pituitary to release adrenocorticotropic hormone (ACTH).
ACTH enters your bloodstream and travels to your kidneys, where it stimulates your adrenal glands to make and release two key adrenal hormones: cortisol and epinephrine.
Epinephrine is a short-acting stress hormone that spikes in stressful situations. Cortisol is a longer-acting stress hormone and helps the body deal with daily stressors. It also spikes during periods of intense stress or in chronic stress. Cortisol has other roles in your body, including:
- Preventing inflammation
- Maintaining blood glucose levels
- Making sure the brain and muscles get enough energy
The body can adapt to temporary increases in cortisol levels. But for reasons that aren’t clear, chronic stress prevents cortisol from functioning correctly.
Another axis comes into play in the body’s physiologic stress response. The hypothalamus-pituitary-thyroid (HPT) axis is the primary feedback loop for regulating thyroid hormones.
Thyroid hormone regulation starts when your hypothalamus releases thyrotropin-releasing hormone (TRH). TRH stimulates your pituitary gland to release thyroid stimulating hormone (TSH). In turn, TSH tells your thyroid gland to release thyroid hormone.
Your body’s overall stress response and thyroid hormone regulation rely on an interplay with the hypothalamus and pituitary gland.
Chronic stress, emotional trauma, and post-traumatic stress disorder (PTSD) can all be causes of cortisol imbalances and can leave us stuck in fight-or-flight mode. In turn, cortisol dysfunction caused by chronic stress contributes to inflammatory autoimmune disease. With an autoimmune disease, the immune system attacks and destroys healthy cells, tissues, glands, or organs.
In fact, a 2016 study found that PTSD increases the risk of developing an autoimmune disorder, including Hashimoto’s thyroiditis, the primary cause of hypothyroidism in the U.S. and one of the most common autoimmune conditions globally.
The researchers found that veterans with PTSD have a higher risk of developing thyroiditis (and other autoimmune disorders) than those without PTSD. While the exact way that PTSD contributes to an autoimmune disease remains unclear, they theorize that PTSD:
- Interferes with the HPA axis
- Increases inflammation
- Changes how the immune system functions
Generally, women are at a higher risk of developing autoimmune disorders than men. But, the above showed that having PTSD increases the risk of autoimmune disease in both men and women equally.
A more recent study of civilian (non-military) women also reported that those with PTSD have a greater risk of developing an underactive thyroid. The study found, however, that PTSD does not increase the risk of developing Graves’ disease, the autoimmune thyroid condition that causes hyperthyroidism.
Another study conducted in 2021 evaluated the activation of the HPA and HPT axes in individuals one year after surviving an earthquake. When comparing cortisol levels before and after the earthquake, cortisol levels were markedly increased. At the same time, TSH levels were reduced, and thyroid hormone levels increased. The study concluded that long-term activation of the HPA occurs following a stressful event. Because of this, the HPA axis recruits the HPT axis to help manage the stress response, affecting thyroid function and potentially triggering an underactive thyroid.
The exact way the HPA and HPT axes influence each other remains unclear. But, as evidence suggests, cortisol levels decrease the function of the HPT axis and increase the risk of autoimmune disorders, including Hashimoto’s and resulting thyroid problems.
If you are experiencing chronic stress or have been diagnosed with PTSD, it’s important to periodically have a complete thyroid test panel to monitor your thyroid function for stress-induced changes. Our complete at-home test kit allows you to conveniently and affordably test your thyroid levels and function without leaving your house.
If you or someone you know needs help coping with emotional trauma, including PTSD, call SAMHSA’s national helpline at 1-800-662-HELP(4357) or visit their website for resources. For Veterans, dial 988, then press 1 for confidential crisis support.