Theory of diseases treated with ephedra decoction, Chinese

Woodcut illustration from an edition of 1833 (13th year of Daoguang reign period of Qing dynasty). The image and text give an account of the principles of diseases treated with ephedra (mahuang) decoction, and the therapeutic effects of the individual ingredients of this remedy. When wind-cold malign Qi stagnates in the muscles and external stratum of the body, blood and Qi do not circulate freely through the vessels, and so one suffers from headache and stiff neck. When wind-cold malign Qi obstructs lung Qi, the lung loses its power to transmit downwards, so the patient is breathless and does not sweat. The bladder channel of foot taiyang connects with the kidney and belongs to the bladder. As the kidney governs the bones, when cold malignance attacks the taiyang channel at the external and muscular level, this can lead to backache and aches and pains in the bones and joints. As wind is a Yang malignance, it tends to affect Yang parts. When the body has been attacked by wind-cold, muscular contractions in the head and headache may occur. All these are symptoms of external excess disorders of the taiyang channel. The recipe contains ephedra, which is pungent, bitter and warming in character, to make defensive Qi permeable and open out the body; cassia twig, which is pungent, sweet and warm in character, to move nutrient Qi and assist the circulation; apricot kernels (xingren), which are bitter and lowering, as an adjuvant to ephedra in restoring the downward-transmitting functions of the lung; and liquorice (gancao), which is sweet and neutral, as an adjuvant to cassia twig in harmonising the interior so as to defend the exterior. With wind-cold excess syndrome of the taiyang channel, this recipe is effective in rapidly expelling the external malignance.

Wind-cold obstructs lung Qi. Breathlessness (chuan). Apricot kernels lower it. When wind-cold rises to the top and is not expelled from the channel, the head aches. When there is cold Qi in the channel, the blood congeals and Qi is blocked, so the head aches and the neck is stiff. The channel passes through the kidney region, therefore there is pain in the small of the back. The kidney governs the bones, therefore there is pain in the bones and joints. Lung Qi is blocked and cannot be moved down, so there is a feeling of oppression in the chest (xiong man). Ephedra unblocks defensive Qi, and treats the condition by producing copious sweating. The continued use of cassia root moves nutrient Qi and promotes circulation. When there is wind-cold in the lung, it causes breathlessness and tightness in the chest, and if it progresses too far, the lobes of the lungs may be turned upside down; therefore apricot kernels should be used.