Based on her 50 years clinical experiences， Professor Lin Lan first put forward the theory that “the thyroid is an extraordinary organ”. She considered that the physiological functions of thyroid refer to help the liver to convey and disperse， and help the kidney to enrich yang; and the pathogenesis of thyroid diseases includes depression， heat， phlegm， blood stasis and deficiency. There are nine common syndromes， including evil fever caused by exogenous pathogens， stagnation of liver qi， the stagnated heat caused by liver depression， qi stagnation and phlegm coagulation， qi stagnation and blood stasis， yin deficiency of liver and kidney， deficiency of qi and yin， deficiency of kidney-yang， and deficiency of yin-yang.