The disease of wind manifests as half-body paralysis. If only the arm is affected and immobile, this is called Bi (impediment). A faint and rapid pulse indicates apoplexy.

bubble_chart Note

The disease of wind is discussed in detail in the Neijing. However, it is often conflated with Bi, leading to confusion among later scholars. Therefore, Zhang Zhongjing reiterated: "The disease of wind manifests as half-body paralysis," which is what the classics refer to as hemiplegia. If only the arms are immobile, it is not apoplexy but rather Bi disease. Generally, Bi is a yin disease, and the pulse is mostly deep and sluggish, whereas wind is a yang disease, and the pulse is mostly floating and moderate. Here, the pulse is faint and rapid, indicating apoplexy. A faint pulse signifies deficiency of healthy qi, while a rapid pulse indicates dominance of pathogenic qi. Thus, in those afflicted by wind disease, those who attract wind due to deficiency invariably exhibit a faint and weak pulse, whereas those who generate wind due to heat invariably exhibit a rapid and urgent pulse.

bubble_chart Collected Annotations

• Shen Ming-zong said: This distinguishes apoplexy from Bi. The disease of wind either injures the defensive qi or infiltrates the nutritive qi, hence it manifests as half-body paralysis, meaning the qi of half the body is impaired and dysfunctional. If only the arm is immobile, this is Bi; Bi means blockage, referring to the obstruction and numbness of qi in a single joint. Upon examining the pulse, it must be faint and rapid; faintness indicates yang deficiency, while rapidness indicates wind. This is caused by apoplexy, meaning wind takes advantage of deficiency to invade, subsequently causing half-body paralysis.