- Hashimoto’s cases rose 30% during the pandemic
- People with thyroid concerns may be affected
- Still early — no immediate treatment changes yet
This study helps explain how global events can affect thyroid health.
You felt tired all the time. Maybe your hair started thinning. You chalked it up to stress. But then came the weight gain — and the doctor said your thyroid was slowing down.
Millions of people live with thyroid problems. And now, a new study shows something unexpected: the pandemic may have changed how often certain thyroid diseases appear.
Thyroid disease affects how your body uses energy. It can make you feel sluggish, gain weight, or struggle with anxiety and heart rate. Two common types are Hashimoto’s Thyroiditis and Graves’ Disease. A third, less common one is Subacute Thyroiditis, often linked to infections.
These conditions impact millions worldwide. Women are far more likely to be affected — especially between ages 30 and 50.
Current treatments help manage symptoms. But they don’t fix the root cause. Many patients cycle through medications, blood tests, and doctor visits just to feel normal.
Now, researchers wanted to know: did the pandemic change the risk of developing these diseases?
The surprising shift
Before this study, doctors noticed more thyroid cases during the pandemic. But was it real — or just more testing?
Some early reports suggested a link between COVID-19 and autoimmune reactions. But data was limited. Most studies were small or focused only on hospitalized patients.
This study is different. It looked at over 4,700 adults in one region of Israel — before and during the pandemic.
But here’s the twist: not all thyroid diseases went up.
What scientists didn’t expect
The study found a 30% rise in new cases of Hashimoto’s Thyroiditis during the pandemic.
That’s significant. Hashimoto’s happens when your immune system attacks your own thyroid. It leads to fatigue, weight gain, and depression.
The increase started before vaccines rolled out. That suggests the virus itself — not the shot — may be the trigger.
Graves’ Disease showed a similar trend, but the numbers weren’t strong enough to confirm a rise.
Here’s what shocked researchers: cases of Subacute Thyroiditis dropped by 54%.
That’s rare. This form usually follows a viral infection — like the flu. Experts thought more viruses would mean more cases.
Instead, it nearly disappeared.
The immune system’s misfire
Think of your immune system like a security team. Its job is to spot intruders and respond fast.
But sometimes, it gets confused. Like a guard who starts attacking the wrong person.
In Hashimoto’s, the immune system mistakenly targets the thyroid — like friendly fire.
The pandemic may have trained this guard to be overzealous. Infections, stress, and changes in daily life could all play a role.
Meanwhile, Subacute Thyroiditis often flares after a cold or flu. With fewer people getting other viruses — thanks to masks and distancing — there were fewer triggers.
So fewer cases made sense.
A closer look at the data
Researchers studied adults aged 16 and older from January 2018 to December 2022.
They tracked new cases of three thyroid diseases using medical records, lab tests, and prescriptions.
They compared two time periods: before the pandemic (2018–Feb 2020) and during (March 2020–Dec 2022).
They adjusted for seasonal swings — so the results aren’t just due to winter colds.
The biggest change? Hashimoto’s diagnoses jumped 30% during the pandemic.
That’s not small. For every 100 cases before, there were 130 during.
This rise began early — even before most people got vaccinated.
Graves’ Disease also trended upward. But the increase wasn’t strong enough to rule out chance.
On the flip side, Subacute Thyroiditis cases dropped more than half.
Fewer people got sick with this type — possibly because fewer viral infections were spreading.
This doesn’t mean this treatment is available yet.
That’s not the full story.
Experts say we can’t blame everything on the virus alone.
Other factors likely played a role: lockdown stress, disrupted sleep, less sun exposure, or even changes in diet.
Still, the pattern is clear: the pandemic didn’t just affect lungs — it may have reshaped immune responses too.
Dr. Ilan Shrier, an epidemiologist not involved in the study, said the findings “add weight to the idea that large-scale health events can ripple through the body in unexpected ways.”
He added: “We’re only beginning to understand the long-term effects of this pandemic.”
If you have a thyroid condition, this study doesn’t change your care plan.
There’s no need to panic or rush to the doctor.
But if you’ve felt unusually tired, gained weight without trying, or noticed changes in your mood or hair, mention it at your next checkup.
Thyroid issues are manageable — especially when caught early.
And if you’re already being treated, keep doing what works. This study doesn’t suggest stopping or changing meds.
More research is needed. Scientists will need to confirm these patterns in other countries and populations.
Long-term tracking will help determine if these changes last — or fade over time.
Until then, this study serves as a warning: global health shocks can leave hidden marks — even after the headlines fade.
