CORONAVIRUS UPDATE: As experts learn more about the novel coronavirus, news and information changes. For the latest on the COVID-19 pandemic, please visit the Centers for Disease Control and Prevention.

When Deborah, a 39-year-old woman in New York, recovered from coronavirus in April 2020, she thought the worst was behind her. But five weeks later, she started to have heart flutters and random adrenaline rushes. She realized whatever was going on was not normal, so she started exploring possibilities with her doctors—and even saw a cardiologist for heart and blood tests.

Eventually, she discovered that thyroiditis was causing her symptoms. For seven months, Deborah had hyperthyroidism, or overactive thyroid. The extra hormones her body produced made her feel jittery, like she’d had too many cups of coffee. Eventually, her thyroid function returned to normal. It was a surprising and long-lasting complication post-COVID-19.

Deborah is not alone. She’s one of a small percentage of people who experienced endocrine system problems brought on by a viral infection, such as COVID-19.

About thyroid problems

The thyroid is a butterfly-shaped gland in the neck that produces hormones that impact your metabolism, growth and development, and body temperature. Thyroid issues range from mild to severe. Around 12% of people will develop a thyroid condition sometime in their lives. Here are a few thyroid issues to watch for:

Hyperthyroidism: Commonly caused by Graves’ disease, an autoimmune disorder in which your immune system attacks your thyroid, this results in an overproduction of thyroid hormone. Toxic nodular disease is another common cause of hyperthyroidism, where a thyroid nodule produces excessive amounts of thyroid hormone.
Hypothyroidism: Commonly caused by Hashimoto’s thyroiditis, which is a condition in which your immune system attacks your thyroid, this results in a decreased production of thyroid hormone.
Subacute thyroiditis: A virus, such as coronavirus, causes an inflammation in the thyroid gland, and often has three phrases, including: hyperthyroidism, hypothyroidism, and then normalizing levels, according to Maria Cardenas, MD, an endocrinologist at Swedish Covenant Hospital in Illinois.
Thyroid cancer: Lumps or lesions can carry the possibility of cancer, but only 10% of the time, Dr. Cardenas says. Doctors can do a biopsy and examine characteristics to determine thyroid cancer. The Centers for Disease Control and Prevention (CDC) list risk factors as too much radiation to the neck area, and genetic predisposition.

Thyroid disease and coronavirus

In the beginning of the COVID pandemic, there were some fears that people who already had autoimmune disorders such as thyroid conditions were immunocompromised and more likely to get coronavirus, according to Alan Christianson, NMD, a medical director of Integrative Healthcare in Arizona. Luckily, those fears were unfounded.

Are people with preexisting thyroid conditions more likely to get coronavirus?

People with thyroid conditions—even autoimmune thyroid disease—aren’t more likely to contract the virus, according to the American Thyroid Association. “I’ve been reassuring people [with thyroid conditions] that those risks don’t apply to them,” Christianson says.

If they do get coronavirus, are they more likely to have complications?

Those who have severely uncontrolled thyroid conditions may have a higher risk of complications once they get a COVID-19 infection. “They are more apt to have hospitalizations,” Christianson says. Additionally, COVID-19 patients who experience major weight gain or weight loss may need an adjustment to their medication dose to keep symptoms in check, Dr. Cardenas says. This can be done at a post-COVID-19 follow-up appointment with your endocrinologist.

Can coronavirus cause thyroid issues in people who didn’t have them before?

Some people who have never had thyroid issues develop subacute thyroiditis (SAT) after recovering from COVID-19. A case series published in The Journal of Clinical Endocrinology and Metabolism in August 2020 follows the cases of four women who developed SAT between 16-36 days after their coronavirus cases had resolved. They’d experienced symptoms associated with SAT such as neck pain (where the thyroid is located) and heart palpitations (a sign of hyperthyroidism). And in a 2022 study of 160 patients with COVID-19, 6.8% developed post-COVID SAT within 3 months of infection. Some experienced neck pain, but others did not.

Dr. Christianson says that the neck pain can be quite obvious, and the area of the neck near where you’d wear a bowtie can be red and swollen. People should also watch for heart issues as the study observed. “If the thyroid is traumatized, it may squeeze a lot out into the bloodstream at once,” Christianson says. “Extra thyroid hormone could cause a heart rate of 120-150 beats per minute.” This could lead you to feel panicky or jittery, especially after you’ve been active or drank coffee.

Christianson explains that SAT occurs in around 10% of patients who have been hospitalized with COVID-19, according to a study published in The Lancet, Diabetes and Endocrinology, in September 2020.

How do doctors treat subacute thyroiditis after coronavirus?

Luckily, most cases of SAT resolve on their own, often without treatment. In other words, it’s a self-limiting condition. Irene Mulla, MD, an endocrinologist with Chicago Health Medical Group, treats this condition with nonsteroidal anti-inflammatory drugs (NSAIDS), such as Motrin or Advil, to help with the neck pain itself. In some cases, she says, more treatment is needed such as steroids.

Some patients like Debbie take comfort in the fact that they know what’s going on, and that most of the time, it will eventually go away. In her case, she chose not to take medication, even though her SAT case persisted for seven months, longer than the one-to-two-month time frame her doctor explained was more typical.

A September 2020 study published in the American Journal of the Medical Sciences recommends to healthcare providers that “supportive care remains the cornerstone of treatment for COVID-19 associated subacute thyroiditis,” and that NSAIDS and beta-blockers such as propranolol in certain cases can help manage symptoms. It goes on to say that in some cases during the hypothyroid phase, a “short course of levothyroxine” may be used until the thyroid resumes regular function.

Dr. Cardenas says some patients may also need support during the “low thyroid” stage of SAT, and then they can wean off the medicine as the thyroid heals itself.

Should I get the coronavirus vaccine if I have a thyroid condition?

None of the healthcare providers hesitated in recommending the COVID-19 vaccine for their thyroid patients, as they aren’t at an increased risk of complications or side effects from it. Dr. Christianson says, “There have not been reports of it worsening autoimmune disease.”

Could I confuse side effects from methimazole with a COVID-19 infection?

Methimazole is a medicine used to treat hyperthyroidism, and Dr. Mulla says the anti-thyroid drug can sometimes come with side effects. The concerning side effect that can mimic COVID-19 involves fever and flu-like symptoms. Dr. Mulla says the only way to tell the difference is to call the endocrinologist to get a blood test to see if a patient is dealing with side effects or COVID-19. While these side effects can happen at any time, she says it typically happens at the beginning of taking a new prescription, or when the dose is high.

Should I delay thyroid-related procedures during the pandemic?

There’s also no reason to postpone your normal thyroid dysfunction checkups, thyroid function tests (TSH tests), or thyroid surgeries due to the pandemic, unless hospital capacity is a concern in your area.