The characteristics of shock are as follows: 1, etiology: a variety of strong pathogenic factors acting on the body caused. 2, pathophysiology: shock is an acute circulatory insufficiency syndrome, its pathophysiology is characterized by a wide range of severe tissue perfusion deficiency caused by insufficient effective blood circulation, and finally cause widespread cellular dysfunction, loss of vital organ function or even life-threatening. The pathophysiological process is characterized by organ ischemia, hypoxia, or impaired tissue oxygen and nutrient utilization and progressive development.3. Clinical manifestations: acute circulatory failure, with inadequate microcirculatory perfusion and impaired cellular function and metabolism as the main manifestations.