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The COVID-19 pandemic has been the leading worldwide health story for several years, and it looks like COVID is with us for good. Since the start of the SARS-CoV-2 virus, researchers have been exploring the relationship between COVID and thyroid conditions and discovering various connections. The good news? COVID viral infection in patients with hypothyroidism has a similar clinical outcome, regardless of whether a patient has pre-existing thyroid disease. The bad news? More than 94 million people in the U.S. have been infected with the COVID-19 virus. And according to new research, COVID-19 infection is a known risk factor for thyroid abnormalities. Ahead, a look at the latest findings and what they mean for you.
In 2021, several observational studies were released that showed a link between COVID-19 infection and changes to the thyroid. Researchers reported that after a COVID-19 infection, some patients with hypothyroidism experienced abnormal thyroid function test results -- specifically transient increases in Thyroid Stimulating Hormone (TSH) levels. While TSH levels doubled in some cases, the changes to thyroid hormone levels were temporary and, over time, returned to normal.
In addition, some people with COVID developed thyroiditis – an inflammatory response of the thyroid gland – which was confirmed by imaging. Thyroid function tests, including antibody tests, remained normal.
We also know from research that hypothyroid patients with COVID have an increased risk of olfactory dysfunction -- namely, an impaired sense of smell known as anosmia.
There is also limited research showing that new diagnoses of hypothyroidism and autoimmune thyroid disease – specifically Hashimoto’s disease and autoimmune hypothyroidism – may occur after COVID infection. There’s also evidence that existing autoimmune thyroid disorders may have worse outcomes after COVID. However, these findings come from smaller studies and require more in-depth research before they are considered definitive.
Researchers have also continued to explore a vital question: are COVID and thyroid problems “bi-directional?” Namely, it’s an issue that raises two questions. First, does COVID infection – or the severity of the infection – cause thyroid problems? And second, does having a thyroid condition put you at higher risk of COVID-19 infection, complications, or adverse outcomes? There haven’t been clear answers about the association between hypothyroidism and COVID until now.
A current study released in the journal Thyroid in August of 2022 finally provided a more definitive understanding of the connection between COVID and thyroid function. In that study, researchers reported that people with a genetic susceptibility to COVID have an increased risk of developing subclinical or overt hypothyroidism.
While longer-term follow-up studies are necessary to confirm the specific degree of increased risk, this is a groundbreaking finding. Almost one-third of Americans have had one or more prior COVID infections. This new research suggests that hundreds of thousands of these individuals may develop an underactive thyroid after COVID-19 infection.
The researchers also found no causal relationship between hypothyroidism and COVID. Specifically, being hypothyroid does not make you more susceptible to COVID infection.
Given this new finding, a crucial question is coming to the forefront. Specifically, is long COVID – defined as debilitating COVID-19 symptoms that continue after active infection – related to post-COVID hypothyroidism? It appears possible that some of the clinical characteristics and symptoms attributed to long COVID may, in fact, be related to pre-existing hypothyroidism. According to the researchers, “…long COVID and hypothyroidism have some common symptoms, such as fatigue, cognitive and mood problems.”
The researchers state that “long-term studies are required to investigate the possible link between long COVID and thyroid function.” While we wait for more definitive information, it makes sense for patients with long COVID to be tested for hypothyroidism.
At this point, it’s clear that having a COVID-19 infection increases the risk of developing hypothyroidism. That means that you, your family members, or friends who have had a prior COVID-19 infection should undergo periodic monitoring of thyroid function. This monitoring should include a complete panel of tests to evaluate levels of thyroid hormones and look for hypothyroidism and thyroid dysfunction.
COVID-19 patients without hypothyroidism should also become familiar with the symptoms of hypothyroidism, such as fatigue, brain fog, cognitive problems, mood changes, body aches, and others. Monitoring for thyroid symptoms after infection can help COVID-19 patients avoid undiagnosed hypothyroidism and the resulting symptoms of an underactive thyroid.
A comprehensive thyroid evaluation – including periodic thyroid testing – is especially important for those with long COVID symptoms. Monitoring and testing can rule out the possibility that undiagnosed and untreated hypothyroidism – not COVID – is the cause of specific symptoms.
You can monitor your thyroid hormone levels and quickly detect hypothyroidism when it develops by taking advantage of affordable hypothyroidism screening with Paloma’s home thyroid test kit. Paloma’s convenient home test kit evaluates Thyroid Stimulating Hormone (TSH), Free Thyroxine (Free T4), Free Triiodothyronine (Free T3), and Thyroid Peroxidase Antibodies (TPOAb). This complete panel provides a detailed snapshot of thyroid function and can confirm autoimmune thyroid disease.
You can also schedule a virtual visit with one of Paloma’s knowledgeable thyroid-savvy practitioners. Paloma’s doctors, available to a majority of Americans around the country, will work with you to carefully monitor your thyroid function, diagnose hypothyroidism, and ensure that you receive optimal thyroid treatment symptom relief.
And, if you’re interested in the effects of COVID-19 vaccination in thyroid patients, read My Experience With Hashimoto’s Hypothyroidism And The COVID Vaccine at the Paloma blog.