Hyperthyroidism is an autoimmune disease, related to mental upset or a history of mental trauma. Its pathogenesis is still not completely known. Generally it is believed that hyperthyroidism is caused by the existence of thyroid stimulus antibody (TSAb). According to the clinical manifestations of the disease, it is categorized in TCM as "ying qi" (goiter), "zhong xiao" (polyphagia), "gan yu" (hepatic stagnation), "gan huo" (hepatic fire) and "xin ji" (palpitation). Its etiological factors are emotional upset, improper diet and unsuitable living conditions, yin-deficiency constitution, etc. At the onset, it is attributed to qi stagnation, liver fire, stagnant phlegm and blood stasis, pertaining to excess type. The prolonged case is often marked by yin deficiency or deficiency of both qi and yin and often involves the liver, heart, spleen and kidney, pertaining to deficiency type.