Can a SARS-CoV-2 infection cause Hashimoto's thyroiditis or other thyroid problems?
SARS-CoV-2 infection has been linked to new cases of autoimmune thyroid diseases, including Hashimoto's thyroiditis. Research indicates that the virus may act as a trigger for the immune system to attack the thyroid in susceptible individuals. This can happen alongside other conditions like hypoparathyroidism or postpartum thyroiditis. However, the virus does not cause these diseases in all people, and the evidence is based on case reports and population studies rather than a single large trial.
What the research says
A 2023 case report described a man who developed Hashimoto's thyroiditis and muscle weakness after a SARS-CoV-2 infection. His thyroid antibodies were negative before the illness, suggesting the virus triggered the autoimmune response 6. Another study reviewed seven similar cases where patients developed Hashimoto's or Graves' disease following COVID-19, supporting the idea that the infection can initiate new autoimmune thyroid disease 6.
Other research shows the virus can trigger different types of thyroid inflammation. One report found a woman developed subacute thyroiditis six days after receiving an mRNA SARS-CoV-2 vaccine, with no other cause found 5. A separate case described a woman who developed postpartum thyroiditis four and a half months after giving birth, one month after her SARS-CoV-2 infection 7. These examples show the virus or the immune response to it can lead to various thyroid issues.
Population-level data from Israel found that the number of new Hashimoto's cases increased during the pandemic compared to the pre-pandemic period 3. This rise suggests a broader link between the infection and the development of this condition. However, the same study noted that findings remain inconclusive because most data come from smaller studies rather than large, controlled trials 3.
What to ask your doctor
- Could my recent SARS-CoV-2 infection be triggering new Hashimoto's thyroiditis or another thyroid problem?
- What symptoms should I watch for if my immune system starts attacking my thyroid after an infection?
- Should I get tested for thyroid antibodies if I had COVID-19 and now have fatigue or weight changes?
- Is there a link between my thyroid condition and other autoimmune diseases like celiac disease or hypoparathyroidism?
This question is drawn from common patient questions about this topic and answered using cited medical research. We do not provide individualized advice.