Did Hashimoto's thyroiditis cases increase during the COVID-19 pandemic in Israel?
Hashimoto's thyroiditis is an autoimmune condition where the immune system attacks the thyroid gland. During the COVID-19 pandemic, doctors noticed more thyroid problems. A large study from Israel looked at whether new cases of Hashimoto's thyroiditis actually increased during the pandemic. The short answer is yes: the study found a clear rise in Hashimoto's diagnoses during the pandemic years compared to before.
What the research says
A population-based study in Israel analyzed over 4,700 new thyroid disease cases from January 2018 to December 2022, using data from Clalit Health Services in the southern district 36. The study compared the pre-pandemic period (January 2018 to February 2020) with the pandemic period (March 2020 to December 2022). Among all new thyroid disease cases, 78.3% were Hashimoto's thyroiditis 36. The interrupted time series analysis showed a statistically significant increase in Hashimoto's incidence during the pandemic 36. This rise was specific to Hashimoto's; in contrast, subacute thyroiditis (a different thyroid condition) actually decreased during the same period 3. The study adjusted for seasonal variations, making the finding more reliable 36. Other research also supports a possible link between SARS-CoV-2 infection and new-onset Hashimoto's. A Chinese study of 369 COVID-19 patients found that 54 (about 15%) were newly diagnosed with Hashimoto's thyroiditis, and prolonged viral clearance was a risk factor 7. However, a review focusing on children found no conclusive evidence of increased autoimmune thyroiditis in pediatric age groups 5. The Israeli study provides the strongest population-level evidence so far, but it cannot prove that COVID-19 directly caused the increase — other factors during the pandemic (like stress, delayed healthcare, or increased testing) may have played a role.
What to ask your doctor
- Could my thyroid symptoms be related to a past COVID-19 infection?
- Should I get tested for Hashimoto's thyroiditis if I had COVID-19 and now feel fatigued or have weight changes?
- How does the increase in Hashimoto's cases during the pandemic affect monitoring or treatment recommendations?
- Are there any specific thyroid checks you recommend for people who had moderate or severe COVID-19?
- If I have Hashimoto's, should I watch for any signs that my condition might have changed after a COVID-19 infection?
This question is drawn from common patient questions about Diabetes & Endocrinology and answered using cited medical research. We do not provide individualized advice.