Hashimoto's thyroiditis, also called chronic lymphocytic thyroiditis, is the first disease to be classified as an immune disorder, by Japanese doctor Hakaru Hashimoto, in 1912 in Germany. It is characterized by the destruction of the thyroid gland by the body's own immune system. It results in hypothyroidism, or insufficient production of thyroid hormones, with brief periods of hyperthyroidism, or overproduction of the thyroid hormones.
The causes of Hashimoto's thyroiditis are not well understood, but there is often a genetic component. It affects about one in every thousand people, and is ten to 20 times more common in women. Most patients are between the ages of 45 and 65.
Hashimoto's thyroiditis causes symptoms associated with other thyroid disorders, including weight gain, constipation, abdominal cramps, high cholesterol, hypoglycemia or low blood sugar, a prickling sensation in the skin, sensitivity to heat and cold, muscle weakness, fatigue, abnormally fast or slow heartbeat, migraines, hair loss, infertility, memory loss, panic attacks, and mania. If untreated, it can cause muscle failure, including heart failure. The thyroid hormone controls the metabolism, or the pace of all the body's processes, so abnormal amounts of the hormone cause a wide range of problems.
Because of the psychological symptoms, Hashimoto's thyroiditis is often misdiagnosed as depression, pre-menstrual syndrome (PMS). It is also sometimes misdiagnosed as bipolar or an anxiety disorder. Identification of anti-thyroid antibodies can help correctly diagnose Hashimoto,'s thyroiditis.
Hashimoto's thyroiditis is treated by replacing thyroid hormone with orally administered levothyroxine or desiccated thyroid extract. The patient must follow the treatment for life in most cases. It is important to maintain the body's levels of thyroid-stimulating hormone, which is secreted by the pituitary gland, but controls thyroid production. Thyroid-stimulating hormone should not exceed 3.0 µIU/mL in a patient with Hashimoto's thyroiditis, or the increased thyroid activity could cause an anti-thyroid immune reaction.