Hashimoto's thyroiditis is an autoimmune disease, and is believed to be top North American cause of primary hypothyroidism. It is also known under the names of Hashimoto's disease and chronic lymphocytic thyroiditis. The name of Hashimoto relates to Japanese physician Hashimoto Hakaru, the first to describe the symptoms.

In the condition, T-cells, which are lymphocytes (a group of white blood cells), invade and attack the thyroid gland. Antibodies against thyroglobulin and/or thyroid peroxidase are present. Although they over time destroy the follicles of the thyroid, they may also be used for diagnosis as they can be clinically detected in the patient's blood.

Main symptoms of Hashimoto's thyroiditis include:

Bradycardia (slow resting heart rate)

Constipation

Depression

Enlarged thyroid area

Fatigue

Hair loss

High cholesterol

Hypoglycemia (reactive)

Infertility

Memory loss

Migraine headaches

Nausea

Panic attacks and mania

Tachycardia (rapid heart rate)

Weight change (weight loss or weight gain)

Once diagnosed, common treatment for Hashimoto's thyroiditis involves thyroid hormone replacement. The medicine typically must be taken for the remainder of the individual's lifetime. Untreated Hashimoto's thyroiditis may lead to muscle failure, including heart failure.