Viruses and Hashimoto’s
How infection affects the thyroid?
Viral infections are some of the most common triggers of thyroid problems and Hashimoto’s (1).
How does it all start?
1. Viruses attack the thyroid gland
Most commonly this happens when viruses attack the throat, nose, and upper respiratory area (sore throat), but also enteroviruses (2–4). Why doesn’t everyone who gets a cold get thyroid problems? Because viruses work together with genetic predisposition (5). Viruses migrate from the throat into the thyroid gland, invade the thyroid cells and start multiplying there. This causes an inflammation of the thyroid.
2. Thyroid autoimmune disease starts
Infection and inflammation cause many different immune cells to move to the thyroid to fight viruses (6,7).
How does this happen? When viruses attack thyroid cells and immune cells come to fight them, the end result is a destroyed thyroid cell, which is chopped in fragments in the process of cell death, called apoptosis. When cells die several things happen: they produce specific molecules and attract immune cells. Immune cells might get confused and recognize parts of the destroyed cell as an enemy. They memorize how these cell parts look like and transfer this knowledge to more immune cells. This is how immune memory works (8).
3. Thyroid becomes (mildly) underactive
This process damages the thyroid. At first the thyroid becomes mildly underactive, but subsequently more and more. This might take a few weeks to months, or be as long as 5 or more years. By this time viruses will be long gone from the body, and may not be detected during a routine lab test.
4. A too-clean environment doesn’t help either
Even though infections trigger autoimmune thyroid problems, having a too-clean environment is not the best solution.
Every time we have a viral infection, our immune system gets smarter, and starts to memorize and better distinguish between the virus and our own body (9,10).
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