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Hot flash or thyroiditis? COVID-19 and thyroid dysfunction

Oct. 11, 2022
"I thought it was weird that as a male I was experiencing a hot flash": Ryan Rutar explains how COVID-19 can affect normal thyroid function, and shares his personal experience with some specific aftereffects.

It’s early morning, and you’re getting ready for work. You know you need a little pick-me-up, so you grab a coffee. As you begin to drink it, you notice you’re feeling a little warmer than usual. You slow down your intake, but the heat intolerance continues. It’s fine, you made it to work, and it’s nicely air conditioned. You chalk it up to taking in a warm liquid that made you feel hot.

As you start on your first patient, you begin to feel warm again. It must be the mask and gloves. But this time it feels different. You notice that you can’t seem to get cool. You start to sweat and feel a little flushed. You excuse yourself and go to the bathroom to throw some cold water on your face. You open your lab jacket to cool off and look in the mirror to see that you have sweat all the way through your shirt. You’re having a hot flash, but the only problem is . . . you’re not over 40, or female.

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This happened to me at the beginning of the year, and I couldn’t figure out what was going on. I thought it was weird that as a male I was experiencing a hot flash. I began to feel along my neck because I was having a bit of a hard time swallowing the past couple of days. I don’t have tonsils; those were removed when I was in first grade. As I began to do an extraoral exam on my neck, I noticed it was tender to the touch when I pushed down along my voice box. The only organ I could think of was my thyroid, and I remembered it being one of the controllers of temperature, along with the hypothalamus.

I went to see my doctor. He, too, thought it might be the thyroid but needed to get some blood work done to determine what kind of problem I could be facing. My blood work came back and showed low levels of TSH (thyroid-stimulating hormone). Normal levels are between 0.4 to 4.0 mIU/L. When someone has low levels of TSH, they are experiencing some form of hyperthyroidism. This is because the thyroid must work harder to make thyroid hormones; hence the sweating and hot flashes. If it is chronic, then it is known as Graves’ disease.1 When you have too much T3 and T4, you burn more energy and lose weight.2 Personally, if it wasn’t uncomfortable, I would say I was one good hyperthyroidism from my ideal weight. Nothing like just sweating the fat off.

On a serious note, if someone has high levels of TSH, they are experiencing some form of hypothyroidism. It shows that the thyroid is needing to be stimulated more, because it isn’t making enough hormone. As such, some people gain weight when experiencing hypothyroidism because their body isn’t using enough energy.2 If it is chronic, it is known as Hashimoto’s disease.

It would make sense if either T3 or T4 thyroid hormones would have been elevated if I were hyper, but they weren’t. So, then we decided on an ultrasound, but that was inconclusive. We moved on to the final and last test. This was the radioactive iodine uptake (RAIU) test, which determines how the thyroid is functioning. If the test shows radiation in the thyroid of 3%–16% in the first six hours or 8%–25% in the next 24 hours, then the thyroid is functioning normally.3 My levels were below normal function, which indicated hypothyroidism.

That’s right, I did not make a typo. My thyroid went from hyper to hypo within four weeks’ time. The radiology tech turned to me and said, “Well, that sounds about right. We have been getting a lot of people with subacute thyroiditis. It’s been happening with people who have now had COVID within the last year. Their inflammatory markers are going into overdrive.”

After hearing her say this, I decided to do a little research on what thyroiditis is and if COVID-19 is affecting people. Thyroiditis is the inflammation of the thyroid gland and usually resolves within a month. Some people may continue to have problems that will usually result in hypothyroidism.1 This used to be an uncommon condition that would occur weeks after a viral infection. This viral infection was usually from the common cold or flu that would infect the ears, sinuses, or throat.

A systematic review showed some emerging evidence that suggests “SARS-CoV-2 can act as a trigger for subacute thyroiditis (SAT).”4 The systematic review looked at 21 cases and showed 81% had fever and neck pain as the common complaints. Some 94% of patients reported some type of hyperthyroid symptoms, while labs confirmed that 100% had low TSH and high T3 and T4.

Why is this important to dental hygienists? I’m bringing this up because we see patients all the time. If you have a patient who is talking about having difficulties swallowing and/or having ear or jaw pain, don’t rule out the thyroid. Try these four steps:

  • Do an extraoral exam on the thyroid to see if the patient has any swelling or any shallow pain with palpating. You can help get them on the right track by recommending they be checked out by their medical doctor.
  • Ask the patient if they have had or been exposed to COVID within the last year.
  • Ask the patient if they have had a cold, flu, or any type of sinus/ear infections recently.
  • Finally, ask if the patient has been experiencing any fevers or temperature changes. It may not be menopause even if they are close to that age.

This condition is now on the rise, and you could save patients some headaches if you are ahead of the curve in your knowledge of the inflammatory response occurring in the thyroid. 

Editor's note: This article appeared in the October 2022 print edition of RDH magazine. Dental hygienists in North America are eligible for a complimentary print subscription. Sign up here.


  1. Thyroiditis. American Thyroid Association. Accessed June 12, 2022. www.thyroid.org/thyroiditis
  2. TSA (thyroid-stimulating hormone) test. Medline Plus. National Library of Medicine. Accessed July 7, 2022. https://medlineplus.gov/lab-tests/tsh-thyroid-stimulating-hormone-test/
  3. What is a radioactive iodine uptake test? UCLA Health. Accessed July 7, 2022. https://www.uclahealth.org/endocrine-center/radioactive-iodine-uptake-test
  4. Rehman MAU, Farooq H, Ali MM, Rehman MEU, Dar QA, Hussain A. The association of subacute thyroiditis with COVID-19: a systematic review. SN Compr Clin Med. 2021;3(7):1515-1527. doi:10.1007/s42399-021-00912-5
About the Author

Ryan D. Rutar, MA, RDH

Ryan D. Rutar, MA, RDH, is president and cofounder of Pearly White Prevention. He consults in dental offices to improve dentist/hygienist relationships and coaches hygienists who want to change the way they deliver care. He has a dual role at Morning Glory Dental private practice as a clinical hygienist and dental hygiene manager. Rutar was a recipient of the 2021 Heart to Hands award by Philips and RDH Magazine and can be reached at pearlywhiteprevention.com.

Updated October 4, 2021