Also known as: Chronic thyroiditis, Autoimmune thyroiditis

What is it?
Hashimoto’s thyroiditis is the most common form of thyroiditis and the most frequent cause of hypothyroidism. Thyroiditis is an inflammation of the thyroid gland. Hypothyroidism is a decrease in thyroid hormone production. Hashimoto’s results from an autoimmune disorder, an attack on the thyroid gland by the patient’s own immune system. The thyroid gland, a butterfly-shaped organ that lies flat against the windpipe in the throat, 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 thyroid antibodies. Those affected may not have any symptoms for several years, but eventually most will experience some degree of hypothyroidism. Symptoms may include weight gain, increased sensitivity to cold, fatigue, dry skin, constipation, weakness, forgetfulness, sluggishness, menstrual irregularities, and hair loss.

About 1 in 1,000 to 50 in 1,000 people will develop this disease at some time in their life. This disorder occurs most commonly in women over the age of 40. It may occur in people with a family history of thyroid diseases or with other autoimmune diseases, especially type 1 diabetes or adrenal insufficiency.