Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, should be seen by an endocrinologist as it is an autoimmune disease. How do we know if it's Hashimoto's thyroiditis? It is typically identified during routine physical examinations that include a thyroid function test. Hashimoto's thyroiditis is characterized by a specific antibody, the anti-thyroperoxidase antibody, also known as Tpoab. Many people may have elevated levels of this antibody, yet their thyroid function, such as free T3, T4, and TSH levels, remains normal. In such cases, it is advisable to initially observe the condition dynamically and to regularly recheck thyroid function, as some individuals may gradually develop reduced thyroid function. Thus, regular monitoring of thyroid function is very important.