Vomiting is a complex pathological or physiological reflex process through the synergistic action of stomach, esophagus, oral cavity, diaphragm and abdominal muscles to expel gastric contents from the stomach and esophagus through the oral cavity, which is divided into reflex vomiting and central vomiting according to the etiology, with the following four main clinical manifestations: First, the characteristics of vomitus: the characteristics of vomitus mainly include the amount, trait and odor of vomitus, etc. A large amount is seen in Pyloric obstruction with gastric retention, acidic odor indicates gastric contents, and foul odor indicates low intestinal obstruction of small intestine. Second, the time of vomiting: vomiting occurs in the early morning is common in pregnancy vomiting, uremia, intracranial hypertension, and vomiting at night is common in pyloric obstruction. Third, vomiting mode: if jet vomiting, mostly seen in intracranial hypertension, glaucoma, while vomiting immediately after meals, small amount, no effort, no nausea, suggesting psychogenic vomiting. Fourth, vomiting accompanied by symptoms: If vomiting is accompanied by high fever, consider acute infection. Vomiting with chest pain, be alert to heart attack or lung infarction. Abdominal pain can be temporarily relieved after vomiting, suggesting a possible peptic ulcer. According to different clinical manifestations and concomitant symptoms, clinical attention should be paid to differentiate and distinguish them and give symptomatic treatment.