The cause of auto-immune thyroid disease is not completely known by medical science. However, a combination of genetic and environment factors are thought to play a role.(30) Molecular Mimicry New theory which explains how an immune system can be "tricked"into attacking the thyroid cells. Yersinia resides in intestinal bacteria has been found to share identical amino acid sequences when compared to the TSH receptor, thyroglobulin, thyroperoxidase , and sodium iodide sympoer . Borrelia burgdorferi has also been implicated This explains the increased antibodies found on lab panels in Hashimoto's patients. These are the antibodies to thyroglobulin and thyroperoxidase (TPO) commonly used by the doctor to confirm a diagnosis of Hashimotos Thyroiditis. TSH Receptor Antibodies Comes in 2 varieties. -First type, the TSH receptor is stimulated-Grave's Disease and hypehyroidism. -Second variety, the TSH recepter is blocked -Hashimotos's disease. -Although both Graves and Hashimotos have a common orign in the molecular mimicry theory -Grave's causes a hypehyroid state, and Hashimoto's causes a hypothyroid state. -Both Graves and Hashimotos antibodies can coexist in the same patient and one can transform into another