In

Treatise on Blood Syndromes

（《血证论》）， TANG Rongchuan proposed the theory of "

yin

-

yang

， water-fire，

qi

-blood"， interpreting the pathogenesis and treatment of insomnia from the perspectives of the mutual generation between water and fire as well as between blood and fire. He considered the "disharmony of blood and fire" in the heart and liver as an important mechanism underlying insomnia. Blood deficiency failing to restrain fire and heart fire harassing the spirit may lead to insomnia， which should be treated by clearing fire and nourishing blood， with

Huanglian Ejiao Decoction

（黄连阿胶汤）.

Yin

deficiency with

qi

stagnation and water retention transforming into phlegm， followed by phlegm disturbing the heart spirit， may cause insomnia， which should be treated by nourishing

yin

， promoting urination， and regulating

qi

， using

Zhuling Decoction

（猪苓汤）. Failure of blood to nourish the liver and the presence of fire in liver channel may result in insomnia， which should be treated by nourishing blood and clearing fire， with

Suanzaoren Decoction

（酸枣仁汤

）. Hyperactivity of ministerial fire and phlegm obstructing

qi

movement， thereby disturbing the liver spirit， should be treated by regulating

qi

and resolving phlegm， with

Wendan Decoction

（温胆汤）. Floating

yang

failing to be restrained and the ethereal soul failing to return to the liver should be treated by restraining

yang

and guiding it back to the liver， with modifications of

Erjia Longgu Decoction

（二加龙骨汤）.