Obstetric shock is divided into the shock compensation phase, the shock suppression phase, and the shock failure phase. A weak pulse that cannot even be clearly touched is a symptom of the shock suppression phase. Differential diagnosis of a weak pulse or even not clearly palpable: 1, slow pulse: slow pulse, a breath of four to, to and from the flaccid and lax pulse. According to Chinese medicine, if the pulse comes evenly and slowly, it is a flat pulse, which is the pulse of a normal person. Slow pulse is mostly seen in dampness or weakness of the spleen and stomach. 2, weak pulse: sink thin and soft like a weak pulse, light seeking no plate heavy picking know, yuan qi depletion essence blood deficiency, teenagers can be considered white head carry on. 3.Weak pulse: the pulse is extremely thin and soft, pressed, seemingly absent. 4, sinking pulse: sinking pulse is one of the pulse. The pulse is low and sunken, lightly taken should not be finger, heavy pressure to get the pulse. Pulse Classic: “The sunken pulse is not enough to lift, press the surplus.” 5, pulse pressure is small: blood pressure is divided into systolic pressure and diastolic pressure, the difference between systolic pressure and diastolic pressure is called the “pulse pressure difference”. For example, the systolic pressure of 120 mm Hg, diastolic pressure of 75 mm Hg, the pulse pressure difference is 45 mm Hg. In general, the normal human pulse pressure difference for 20-60 mm Hg (2.67-8.0Kpa), greater than 60 mm Hg for the pulse pressure difference is too large, less than 20 mm Hg is too small. 6, odd pulse: refers to the phenomenon that the pulse is significantly weakened or even disappears when inhaling, and then appears or returns to its original state when exhaling. Observe the odd pulse with a sphygmomanometer, often more obvious than finger palpation.