《黄帝内经·灵枢·刺节真邪》
岐伯说：人得了中风一类的病，血气必有偏虚之处，虚者是指正气不足，实者是指邪气有余，这样身体就感到肢体轻重不相称，身体倾斜反侧，仆伏欲倒，严重时可导致神志昏乱，意识模糊，不能辨别东西南北，症状出现忽上忽下反复多变，颠倒无常，所以它比单纯的神志迷惑还要病情严重。
岐伯曰：大风在身，血脉偏虚，虚者不足，实者有余，轻重不得，倾侧宛伏，不知东西，不知南北，乍上乍下，乍反乍复，颠倒无常，甚于迷惑。
Qi Bo said: When someone gets a stroke-like illness, there must be a partial deficiency or excess of Qi and blood. Deficiency refers to insufficient righteous Qi, while excess refers to an excess of evil Qi. This causes a feeling of uneven weight and lightness in the body, tilting of the body to one side, a desire to fall down, and in severe cases, mental confusion, blurred consciousness, and inability to distinguish directions. The symptoms appear suddenly and repeatedly, are erratic and unpredictable, and are therefore more serious than simple mental confusion.