Nausea and vomiting may be caused by physiological factors such as diet and pregnancy, as well as pathologic factors such as gastrointestinal diseases, liver and gallbladder diseases, cardiovascular system diseases, urinary system diseases and thyroid diseases. 1. Physiological factors: If the patient eats too much cold and spicy stimulating food such as chili peppers and cold drinks, or foods that are difficult to digest such as deep-fried, sweet and greasy foods, or if there is overeating or a cold abdomen, it will affect the digestion and absorption of the gastrointestinal tract and lead to nausea and vomiting. If women of childbearing age experience nausea and vomiting, they should also consider the possibility of pregnancy. 2. Gastrointestinal diseases: such as acute and chronic gastroenteritis, peptic ulcer, inflammatory bowel disease, gastrointestinal tumors, etc., can lead to gastrointestinal mucosal damage, causing gastrointestinal dysfunction, so that the patient appears nausea and vomiting symptoms. 3. Hepatobiliary diseases: such as alcoholic liver, fatty liver, cirrhosis, liver cancer, cholecystitis, gallstones, etc., which can affect the production or discharge of bile, affecting the digestion and absorption of fat, and make patients feel nausea and vomiting. 4. In addition to digestive system diseases, other system diseases can also cause nausea and vomiting, such as cardiovascular system diseases, cardiac failure, myocarditis, cardiac infarction; urological system diseases, renal failure, adrenal disease; respiratory system diseases, respiratory failure, lung cancer; thyroid diseases, hyperthyroidism or hypothyroidism; neurological system diseases, cerebral infarction, cerebral hemorrhage; nephrotic syndrome and so on. It is necessary to identify the patient according to the accompanying symptoms and test results. Patients who vomit more than once should go to the hospital as soon as possible to find out the cause, so as not to delay the treatment.