The causes of pregnancy vomiting are two major aspects: 1, endocrine factors, the body chorionic gonadotropin level is elevated, pregnancy vomiting is related to the increase of HCG level, such as gravidas, twin pregnant women have a higher chance of pregnancy vomiting. Changes in thyroid function, such as early pregnancy may appear transient hyperthyroidism, the severity of vomiting in pregnancy is related to the level of free thyroid hormone, the occurrence of vomiting in pregnancy at the same time, you can carry out the measurement of thyroid function; 2, mental stress, anxiety, worry, as well as the living environment and economic conditions of the poor pregnant women are more likely to occur vomiting in pregnancy. For pregnant women with severe vomiting of pregnancy, family members should give more care and comfort to ease the severe vomiting of pregnancy caused by excessive tension and anxiety.