Article updated April 13, 2021.
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COVID-19 is a respiratory disease caused by SARS-CoV-2, a new coronavirus discovered in 2019. The virus spreads from person to person through respiratory droplets and has affected millions of people worldwide.
Most people recover from COVID-19 within weeks to months of illness. However, some people experience long-COVID symptoms for more than four weeks after being infected with the SARS-CoV-2 virus.
Experts aren't sure why or how some people experience long-COVID but are actively investigating the causes of post-COVID conditions.
Long COVID is an array of symptoms that can last for weeks or months after initially contracting the SARS-CoV-2 virus. Research suggests that 10 to 30 percent of people who recover from COVID-19 may develop long COVID.
Anyone who has had COVID-19 can experience long COVID, regardless of the severity of their symptoms. People with long COVID report having different combinations of the following symptoms:
- Tiredness or fatigue
- Brain fog
- Loss of smell or taste
- Dizziness on standing
- Heart palpitations
- Chest pain
- Difficulty breathing
- Shortness of breath
- Joint or muscle pain
- Depression or anxiety
- Symptoms that worsen after physical or mental activities
Researchers find that moderate to severe COVID-19 illness may trigger inflammation of the thyroid gland in some patients.
In fact, about 10 percent of hospitalized COVID-19 patients with no history of thyroid disease might develop subacute thyroiditis (a temporary thyroid condition) even after recovering from COVID-19 illness.
What is subacute thyroiditis?
Subacute thyroiditis is an inflammatory disease of the thyroid likely caused by a virus. Symptoms include fever and tenderness in the neck. With subacute thyroiditis, initial hyperthyroidism is common, sometimes followed by a short period of hypothyroidism. A thyroid blood test can help confirm the diagnosis.
Now, research finds that people who experience thyroid inflammation related to COVID-19 illness may still have thyroid dysfunction even in the months following recovery from COVID-19.
More research is needed to understand why COVID-19 may cause ongoing thyroid dysfunction. Still, experts suggest that formerly hospitalized COVID patients continue to test their thyroid every six months.
Most cases of subacute thyroiditis are self-limiting, meaning that they typically resolve on their own without treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs, like aspirin or ibuprofen) or beta-blockers (used to reduce blood pressure) may help manage subacute thyroiditis symptoms. If symptoms are severe during the hypothyroid phase, a short course of thyroid hormone replacement medication may help until the thyroid resumes regular function.
Otherwise, patients can expect a gradual improvement of their long COVID symptoms over time. Still, we recommend that you talk to your healthcare provider about options for managing or treating your specific long COVID symptoms.
The best way to prevent long COVID complications is to take measures to prevent the spread of COVID-19.
- Wear a mask covering your nose and mouth
- Maintain six feet of physical distance between you and others
- Get a COVID-19 vaccine when it becomes available to you
- Avoid crowds or poorly ventilated indoor spaces
- Wash your hands frequently with soap and water
An informal survey by Survivor Corps, a patient advocacy group, found 38 percent of people with long COVID said their condition improved after receiving their COVID-19 vaccination.
More research is needed to understand why the COVID-19 vaccination may help people with long COVID. "Thus far [this issue is] anecdotal," says Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Dr. Fauci explains that many people spontaneously recover from COVID-19, so it's hard to distinguish if this outcome is from the vaccine or spontaneous recovery. He says, "you'll have to do a randomized trial to determine that."
The science behind why the vaccine might reduce long-COVID symptoms is unclear.
One suggestion is that people with lingering symptoms of COVID-19 may still have live coronavirus in the body. The immune response caused by the COVID-19 vaccine may eliminate any remaining virus, reducing symptoms.
Another possibility is that viral infections, like COVID-19, can trigger inflammation of the thyroid gland. In this instance, the vaccine may provide temporary relief from an inappropriate immune response.
More extensive studies are still needed to understand long COVID fully. The National Institutes of Health (NIH) recently received over a billion dollars in funding to support research into the long-term health consequences of COVID-19. The NIH will use this funding to research how many people are affected by long COVID and the underlying mechanisms of this condition.
Clearly, we're still learning about how and why vaccines may relieve symptoms of long COVID. However, thyroid patients who have recovered from short-term symptoms of COVID-19 can still safely get vaccinated.
Paloma Health thyroid doctor Dr. Sapna Shah says, "I recommend that all patients with thyroid disease receive the COVID-19 vaccine. Currently, there isn't any known reason why a patient with thyroid disease should not receive the COVID-19 vaccine, and the benefit of the vaccination far outweighs any potential risk."
The Centers for Disease Control and Prevention (CDC) recommends that people wait until they have completely recovered from the short-term symptoms of COVID-19 to receive their vaccination.