Vomiting in early pregnancy is mainly due to two factors: first, the patient’s pregnancy is caused by an increase in blood chorionic gonadotropin level, which is one of the main causes of vomiting. This is the main cause of vomiting. Generally, vomiting starts to appear around 40 days of pregnancy, reaches its peak around 2 months of pregnancy, gradually decreases after 2 months, and basically disappears around 3 months. Such a change curve basically corresponds to the peak growth of blood chorionic gonadotropin and the stable period, so it is considered that vomiting in early pregnancy is closely related to the increase of blood chorionic gonadotropin. Second, the main consideration is the individual differences, most of the patients who vomit more violently are weaker, or have some gastrointestinal diseases. Generally, patients who are stronger or have better gastrointestinal function will have mild or no vomiting symptoms.