What is hashimoto's disease? how does it affect hypothyroidism?

Autoimmune: Hi. Hashimoto's (Hash) is the most common cause of non-surgical hypothyroidism, and is an autoimmune disease. It is commonly diagnosed by serum thyroid autoantibodies (TPO and thyroglobulin), and much less commonly by fine needle aspiration biopsy. Hash only causes disease when it destroys thyroid function. Hash antibodies do NOT cause disease, and are only a marker for thyroid autoimmunity.