Hashimoto’s disease, or Hashimoto’s thyroiditis, is an autoimmune disease. That is, your immune system, which should be defending your body against germs and viruses, begins to destroy your thyroid gland mistakenly.
The thyroid gland is a small, butterfly-shaped gland at the base of your neck. It makes hormones that regulate your metabolism, influence energy, heart rate, digestion, and more.