Unfortunately, there is no known way to prevent Hashimoto's thyroiditis (or inflammation of the thyroid gland. But on the bright side, this disorder is very treatable. The sooner you get diagnosed, the sooner you can start receiving treatment.
Hashimoto's thyroiditis is an autoimmune disorder. In other words, it's caused by a malfunction of the immune system. It's still not fully understood why the immune system attacks the body's healthy tissues instead of protecting them, so preventing that mechanism isn't currently possible.
Since you can't prevent this disorder, it's that much more important to recognize the symptoms of Hashimoto's thyroiditis . If you understand the symptoms and visit your doctor as soon as possible after recognizing them, you'll have the best chance of preventing the disease's progression.
Like any disease, diagnosing Hashimoto's thyroiditis early is important because it gives you earlier access to treatment. Some of the most common symptoms of Hashimoto's thyroiditis—hypothyroidism and goiter—are highly responsive to treatment. You can read more about this in our article about thyroid hormone replacement therapy for Hashimoto's thyroiditis.
Though prevention isn't possible when it comes to Hashimoto's thyroiditis, keep in mind that this thyroid disorder is very treatable. If you are concerned about the presence of any possible symptoms, don't hesitate to discuss them with your doctor.