Last Chance - Mother's Day Sale

Last chance - Mother's Day Sale

For moms, thyroid health matters. Save $25 on our thyroid test kit or self-pay membership using code MOMDAY.

5 Common Triggers of Hashimoto's Flare-Up

Learn about the top five triggers of autoimmune flare-ups and how to avoid them.
5 Common Triggers of Hashimoto's Flare-Up
Last updated:
Medically Reviewed by:

In this article

Hashimoto’s is an autoimmune disease where the body mistakenly produces antibodies that attack the thyroid. This attack leads to inflammation and thyroid damage over time. That damage to the thyroid gland can impair the production of thyroxine (T4) and triiodothyronine (T3), the two most essential thyroid hormones. These hormones help regulate your metabolism as well as many other body functions. In fact, nearly every cell in your body needs thyroid hormone to function correctly.

Eventually, many people with Hashimoto’s develop hypothyroidism, an underactive thyroid.

Despite proper management of Hashimoto’s, individuals can still experience a flare-up. Why does this happen? Please keep reading to find out and learn five common triggers of flare-ups and ways to avoid them.

Understanding Hashimoto’s flare-ups

A Hashimoto’s flare-up occurs when the immune system, designed to protect the body from harmful substances, mistakenly ramps up its attack on the thyroid gland. During a flare-up, the immune system becomes hyperactive and releases inflammatory substances that can inflame and damage the thyroid. 

A flare-up can occur unpredictably and vary in duration and intensity. Most flare-ups are accompanied by worsening or intensifying symptoms.

During a flare-up, the immune system increases its attack on the thyroid, and this autoimmune reaction can result in new or worsening Hashimoto’s symptoms, including:

  • Extreme fatigue
  • Weight gain
  • Constipation
  • Cold intolerance
  • Changes in mood or cognition, like worsening depression or brain fog
  • Trouble sleeping
  • Joint pain and muscle aches
  • GI distress like bloating or acid reflux

People with Hashimoto’s disease should be aware of their risk factors for a flare-up and identify their unique stressors and triggers so they can be avoided whenever possible. To help, let’s take a more in-depth look at several of the most common triggers.

Triggers that can cause a flare-up

A flare-up of an autoimmune condition like Hashimoto’s can be triggered by various factors. These can include insufficient treatment of the condition, nutritional factors, inadequate sleep, stress, and exposure to certain chemicals, toxins, and infections. In addition, certain medications, hormonal changes, and a lack of exercise can also contribute to the occurrence of autoimmune flare-ups. 

We are all exposed to these types of stressors every day. So, flare-ups are still possible even with proper management of Hashimoto’s. Let’s look at five of the most common triggers of Hashimoto’s flare-ups. 

Suboptimal thyroid medication dose

Most patients with hypothyroidism resulting from Hashimoto’s manage the condition by taking thyroid hormone replacement medication. These medications help raise thyroid hormone levels back to a normal range. But sometimes, thyroid levels can drop, even if you take your medication as prescribed.

Hormonal fluctuations -- like those that occur during pregnancy, menstruation, or menopause -- can be to blame. How you take your medication also matters. For instance, levothyroxine is best taken on an empty stomach, separated from other foods and medications. Why? Medications, including over-the-counter and supplements, can prevent your body from absorbing the full levothyroxine dose. As a result, thyroid levels remain low despite you taking your thyroid medication, causing a flare-up.

If you notice that you are experiencing hypothyroid symptoms despite treatment, talk with your provider. They may recommend checking your thyroid levels to ensure your thyroid hormone levels are optimal

Dietary triggers

A healthy and balanced diet can play a significant role in managing Hashimoto’s symptoms and avoiding flare-ups. Focus on incorporating nutrient-rich foods such as fruits, vegetables, lean proteins, and healthy fats into your diet. Additionally, following an anti-inflammatory diet that reduces or eliminates processed foods, sugary snacks, and beverages can help, as these foods contribute to inflammation and can worsen symptoms.

Certain foods can trigger flare-ups in individuals with Hashimoto’s disease. Common triggers include dairy, soy, and processed foods. Although the specific triggers can vary from person to person, consider keeping a food diary to identify any patterns between your diet and flare-ups. By eliminating or reducing these trigger foods, you may experience fewer symptoms and a reduced risk of flare-ups.

One of the most trigger foods is gluten. Gluten has been a hot topic lately, and when it comes to Hashimoto’s flare-up triggers, it deserves close attention! Gluten is a protein in wheat, rye, barley, and other grains. But, many other food items contain gluten, often hidden unexpectedly. Other foods that have gluten include sauces, salad dressings, and candy bars.

There is a connection between celiac disease and Hashimoto’s disease. About 5% of adults with Hashimoto’s also have celiac disease. Experts believe gluten may cause the immune system to produce autoantibodies that destroy the thyroid. Thus increasing thyroid inflammation and further hindering thyroid hormone production.

Another theory is that gluten may irritate the small intestine, causing inflammation. As a result, intestinal permeability increases due to weakened intestinal junctions (a.k.a leaky gut). And weak intestinal junctions allow toxins like bacteria to escape from the gut into the bloodstream. Your immune system recognizes these toxins as invaders and begins to attack them, further increasing inflammation.

But, evidence on whether a gluten-free diet benefits everyone with Hashimoto’s is a bit mixed. If you notice gluten triggers Hashimoto’s symptoms, talk to your provider. You may have an undiagnosed gluten sensitivity that needs to be addressed.

Now, gluten isn’t the only food that can affect your GI system. Many other foods can also cause dietary stress, causing GI upset, chronic inflammation, and a possible elevation in thyroid antibodies. Exposure to these foods may cause symptoms like diarrhea, bloating, acid reflux, gas, or cramping in the GI tract. You may also experience respiratory, muscular, or skin symptoms. Keeping track of which foods cause these symptoms can help you identify and avoid these triggers in the future.

Insufficient sleep

Getting enough quality sleep is a cornerstone of overall health. Disruptions in your sleep pattern or insufficient quality sleep can impact your thyroid health.

If you have trouble falling or staying asleep or you regularly get low-quality sleep, you could be setting yourself up for a Hashimoto’s flare-up. Use these tips to improve your sleep:

  • Plan for seven to nine hours of sleep each night
  • Do some form of physical activity every day
  • Don’t bring technology into your bed or bedroom
  • Address underlying sleep conditions, like sleep apnea
  • Ask your provider if a sleep aid like melatonin would be helpful 

Chronic stress

Stress can trigger a flare-up, whether due to work pressures, personal challenges, poor nutrition, or lifestyle demands.

When stressed, your adrenal glands produce cortisol, a.k.a. the stress hormone. And chronic stress can lead to a sustained elevation in cortisol levels. In turn, this can impact your thyroid function, increasing the likelihood of flare-ups.

Managing stress is essential to protect or calm your body from an autoimmune flare-up. Here are ways to help reduce stress:

  • Aim for seven to nine hours of quality sleep each night
  • Eat nutrient-dense foods to fuel your body
  • Move your body a little bit each day
  • Practice mindfulness or relaxation techniques
  • Connect with those who are important to you

Toxic and infectious exposures

Exposure to environmental factors, ranging from pollutants to heavy metals, can also contribute to Hashimoto’s flare-ups. In addition, bacterial or viral infections like the flu or COVID-19 are also potential triggers that may cause a flare-up. The reason is that a virus or bacteria activates the immune system, as it should. This results in inflammation as your body tries to fight it off. And too much inflammation in the body can trigger a flare-up.

Some environmental factors are unavoidable, like toxins in the air. However, there are ways to reduce exposure to potential environmental triggers, including

  • Washing your hands frequently and avoiding touching your face
  • Opting for chemical-free, natural cleaning products
  • Being mindful of consuming mercury-containing fish
  • Using indoor air filters
  • Avoiding second-hand smoke

A note from Paloma Health

Understanding and managing triggers for Hashimoto’s flare-ups is crucial for maintaining your thyroid health and avoiding troublesome symptoms. By identifying and avoiding your potential triggers, such as stress, poor sleep, dietary issues, and toxic exposures, you can reduce the frequency and severity of Hashimoto’s flare-ups. As a Paloma Health member patient, you can have access to a thyroid practitioner who can help you develop a tailored treatment plan to manage your symptoms and improve your overall thyroid health. By working closely with your Paloma Health provider, you can better understand your unique triggers, make informed lifestyle changes, and optimize your medication regimen to reduce flare-ups and achieve better overall health. You may also want to add a Paloma nutritionist to your team, given that diet is a common trigger of flare-ups. At Paloma Health, you can access thyroid experts and nutritionists all from the comfort of your home. Make an appointment for a free consultation today.

Thyroid care online

Dealing with Hypothyroidism?  Video chat with a thyroid doctor

Get answers and treatments in minutes without leaving home - anytime. Consult with a U.S. board certified doctor who only treats hypothyroidism via high-quality video. Insurance accepted.


Szczuko M, Syrenicz A, Szymkowiak K, Przybylska A, Szczuko U, Pobłocki J, Kulpa D. Doubtful Justification of the Gluten-Free Diet in the Course of Hashimoto's Disease. Nutrients. 2022 Apr 21;14(9):1727. doi:

Obrenovich MEM. Leaky Gut, Leaky Brain? Microorganisms. 2018;6(4):107. doi:

CDC. Sleep hygiene tips - sleep and sleep disorders. Centers for Disease Control and Prevention. Published September 13, 2022. Accessed January 10, 2024.

Yaribeygi H, Panahi Y, Sahraei H, Johnston TP, Sahebkar A. The impact of stress on body function: A review. EXCLI J. 2017;16:1057-1072. doi:

Share article:

Emilie White, PharmD

Clinical Pharmacist and Medical Blogger

Emilie White, PharmD is a clinical pharmacist with over a decade of providing direct patient care to those hospitalized. She received her Doctor of Pharmacy degree from Massachusetts College of Pharmacy and Health Sciences. After graduation, Emilie completed a postgraduate pharmacy residency at Bon Secours Memorial Regional Medical Center in Virginia. Her background includes caring for critical care, internal medicine, and surgical patients.

Read more

Is Paloma Right For Me?

Hypothyroidism is a long-term commitment and we’re committed to you. Schedule a free, no-obligation phone consultation with one of our intake specialists to find out more.

Schedule a call
thyroid hormone for hypothyroidism

Find out if Paloma is right for you. Schedule a free call with one of our health care advisors.

Schedule a Call