Fast Facts: Hashimoto's thyroiditis
- Hashimoto's thyroiditis is an autoimmune condition that is the most common cause of hypothyroidism (underactive thyroid).
- During the initial stages of Hashimoto's thyroiditis, the thyroid can release stored thyroid hormone, leading to symptoms of hyperthyroidism, such as rapid heart rate, tremors, heat intolerance, unexplained weight loss, and excessive sweating.
- The hyperthyroid stage of Hashimoto's thyroiditis can be distinguished from Graves' disease via antibody testing (the presence of TSI or TRAb will confirm Graves' disease) or via a Radioactive Iodine Uptake & Scan, which provides a snapshot of how the thyroid is taking up iodine. Graves' disease typically results in a high uptake all over the thyroid, with Hashimoto's thyroiditis resulting in low uptake.
- Over time, Hashimoto's thyroiditis results in hypothyroidism, which is treated by taking thyroid hormone replacement - brand name or generic levothyroxine - typically for life. Some patients report improved symptom management and quality of life with T3/T4 combination therapy, although futher studies are needed in this area.