What is Hashimoto thyroiditis?
Hashimoto thyroiditis is the most common form of thyroid gland inflammation (thyroiditis) and the most frequent cause of decreased thyroid hormone production (hypothyroidism). It results from an autoimmune disorder, an attack on the thyroid gland by a person's own immune system. The thyroid gland is a butterfly-shaped organ that lies flat against the windpipe in the throat. It produces the hormones thyroxine (T4) and triiodothyronine (T3) and plays an important role in controlling the body's metabolism. With Hashimoto thyroiditis, the thyroid becomes enlarged (called a goiter), firm, and rubbery but not usually tender. Thyroid gland tissue is slowly destroyed by lymphocytes that move into the thyroid gland and by one or more thyroid autoantibodies. This causes a progressive decrease in the production of thyroid hormones.
About 1 in 1,000 to 50 in 1,000 people will develop this disease at some time in their life. This disorder can affect anyone at any age but occurs most commonly in women who are over the age of 40. It may occur with increased frequency in those with a family history of thyroid diseases or with other autoimmune diseases, especially type 1 diabetes or adrenal insufficiency.