Inadequate tissue perfusion is a unique manifestation of shock. When the body is in shock, such as reduced blood volume or infectious shock, the body must first ensure the blood supply of important organs such as the brain, heart, bilateral kidneys, etc., so it will lead to some manifestations of insufficient perfusion, ischemia and hypoxia in the local tissues. In the early stage of shock, the microcirculation will be closed to the input small arteries. In the bruising phase of shock, due to the production of some inflammatory mediators in the microcirculation, etc., it can lead to the opening of the input arteries and the closing of the output arteries, which will lead to the bruising in the tissues, and after a long time, the patient may have symptoms such as DIC and lactic acid increase.