The lack of appetite may be caused by the patient’s dietary structure changes, mental factors, pregnancy, gastrointestinal dysfunction and so on. 1. Dietary structure change: patients without appetite may be a sudden change of dietary structure, such as often eat light food suddenly eat greasy food and other situations. 2. Mental factors: the lack of appetite may be caused by mental tension and anxiety due to work pressure and school pressure. 3. Pregnancy: some patients may have no appetite due to the effect of human chorionic gonadotropin during pregnancy, which may also cause vomiting in severe cases. 4. Gastrointestinal dysfunction: It may be due to irregular diet or eating cold and irritating food, which leads to gastrointestinal dysfunction, thus resulting in the phenomenon of lack of appetite. If the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, under the guidance of a doctor to determine the cause of the disease and targeted treatment, do not take medication, so as to avoid delays in the condition.