Chinese medicine holds that the blood gives rise to the body's vital energy, which falls into five categories--named after the Five Elements of metal, wood, water, fire and earth--which have a growth-promoting or growth-inhibiting effect on one another.
中醫說「氣血」，有血才能產生氣，氣就是能量。能量又分成五大類﹘ ﹘金木水火土，也就是五行﹘﹘彼此相生相剋。