According to the pathophysiological classification, the four subtypes of shock are divided into volume shock, cardiogenic shock, distributive shock and obstructive shock, as follows: 1, low volume shock: is low blood volume, mainly blood loss or a large amount of body fluid loss, burns, trauma or inflammatory exudation, diarrhea, can lead to insufficient blood volume, it is called volume shock; 2, distributive shock: mainly is not obvious The blood loss, fluid loss, but the distribution of body fluids around the body such as anaphylactic shock, cardiogenic shock; 3, cardiogenic shock: the main problem is from the heart, the heart output is insufficient to lead to insufficient peripheral circulating blood; 4, obstructive shock: mainly pulmonary embolism, arterial stenosis or pulmonary hypertension, constrictive pericarditis, because the blockage of blood vessels lead to the overall circulation of insufficient blood volume.