Stomach pain and vomiting can be caused by gastric and duodenal diseases, diseases of the hepatobiliary and pancreatic systems, and acute appendicitis. The specific causes need to go to the hospital for formal examination. 1. Diseases of the stomach and duodenum: chronic gastritis, acute gastritis, peptic ulcer, acute gastric dilatation, pyloric obstruction, functional dyspepsia and so on. They are characterized by irregular diet and over-eating. 2. Diseases of liver, gallbladder and pancreatic system: acute hepatitis, acute cholecystitis, cirrhosis, hepatic stasis, chronic cholecystitis and pancreatitis. It manifests as stomach pain, nausea, vomiting, and inflammation of gallbladder and pancreas manifests as severe abdominal pain accompanied by abdominal distension. 3. Acute appendicitis: the main feature is metastatic right lower abdominal pain, manifested as stomach pain, nausea, vomiting. It is necessary to go to the hospital to do routine blood tests and ultrasound of the appendix at the same time, which can make a clear diagnosis. Severe stomach pain and vomiting symptoms should be timely to the regular hospital, by the doctor to clarify the cause of the disease, give targeted treatment.