Nausea and vomiting may be caused by pregnancy reaction, acute gastroenteritis, viral cold and other factors. 1. Pregnancy reaction: After pregnancy, the level of human chorionic gonadotropin in the body will increase. Under the action of this hormone, the symptoms of nausea and vomiting may occur. 2. Acute gastroenteritis: when acute inflammation occurs in the gastrointestinal tract due to bacterial and other pathogenic microbial infections, the role of inflammatory mediators in the body, nausea and nausea symptoms may occur. 3. Viral colds: when the virus infects the human body, under the action of the virus and its metabolites, there may be a difficult situation. If this involves the gastrointestinal tract, the gastrointestinal tract is affected, then the symptoms of nausea and vomiting may occur. There may be other reasons for the nausea and vomiting. When the nausea and vomiting occur, you should consult a doctor in time, under the guidance of the doctor, improve the measurement of the level of human chorionic gonadotropin, fecal bacterial culture, blood tests, etc., to clarify the cause of the disease, and actively treat it.