When the causative factors act on the organism, the pathophysiological process of shock has already started, and the microcirculation and clinical manifestations of the patient have been altered accordingly before the typical clinical fall in blood pressure occurs. According to the alteration of microcirculation, shock is divided into 3 stages, namely, microcirculatory ischemic phase, microcirculatory stasis phase and diffuse intravascular coagulation phase, also known as early shock, shock phase and late shock phase, as follows: 1. Early shock phase: equivalent to microcirculatory spasm ischemic phase, belongs to shock compensatory phase, when the effective blood volume is reduced to less than 20%, due to the compensatory effect of the organism, the excitability of central nervous system is increased and Sympathetic excitation, clinical performance is characterized by nervousness, irritability, pallor, cold limbs, fine pulse, rapid heartbeat, little change in blood pressure, reduced pulse pressure, and normal or reduced urine output. At this time, if timely treatment, shock can be quickly corrected, if not handled properly, the condition will continue to deteriorate and enter the next stage; 2, shock period: equivalent to the microcirculatory expansion period, performance is characterized by indifference, unresponsiveness, and even blurred consciousness, skin mucosa from pale to cyanotic, cold extremities, weak pulse, superficial venous sink, blood pressure drop, shortness of breath, reduced urine volume, etc., the condition of this period is serious If you can actively resuscitate, you can still be saved; 3, the late stage of shock is also known as shock decompensation: equivalent to the microcirculatory failure period, performance characteristics of a very weak pulse or no pulse, no blood pressure, coma, no urine, the whole body bleeding tendency, there are bruises under the skin mucosa, and can appear hemoptysis, vomiting blood, blood in the stool, blood in urine and other extensive bleeding, and even secondary to multi-system organ failure.