The term “Hashimoto” refers to Hashimoto’s thyroiditis, a chronic autoimmune disease of the thyroid gland, first reported by Hashimoto in Japan in 1912. The exact cause of Hashimoto’s thyroiditis is unknown and may be related to genetic, immunologic, and environmental factors. Hashimoto’s thyroiditis is one of the main types of autoimmune thyroiditis and is the most common type of thyroiditis in the clinic, characterized by massive lymphocytic infiltration. Hashimoto’s thyroiditis has an insidious onset and progresses slowly. Early manifestations are often atypical, and in the middle and late stages, hypothyroidism (fatigue, decreased concentration, weight gain, constipation, etc.) may be present, requiring thyroid hormone replacement therapy. Hashimoto’s thyroiditis needs to be diagnosed and treated under a doctor’s supervision.