Internal wind refers to the pathological phenomenon of limb jitter and tremor caused by excessive yang in the body. It is called "wind" because it only means "the wind wins the motion" and uses sports to describe the wind. Clinically, there are all symptoms such as dizziness, stiff limbs, sudden fainting, eye suspension, mouth and eye deviation, hemiplegia, or spasm, tremor, numbness of limbs, muscle weakness, hand and foot peristalsis. Most of them are pathological phenomena of endogenous wind, in which tonic spasm, debilitating peristalsis or involuntary tremor are the syndrome characteristics of endogenous wind. As for the causes of endogenous wind, there are heat-induced wind, liver-yang wind, yin-deficiency wind and blood-deficiency wind. Because of the different causes of internal wind, its "dynamic" performance is also different. Generally speaking, it can be divided into two types clinically: excess wind and deficiency wind.
Sometimes there is a connection between the external wind and the internal wind. The synopsis of the golden chamber holds that the cause of stroke is related to the emptiness of collaterals, the lack of vital qi, and the wind evil taking advantage of deficiency and people. For example, hypertensive stroke (mostly liver yang turning to wind) can sometimes be caused by exogenous wind and cold, so the incidence rate is higher in winter and spring (more cold in winter and windy in spring).