In the early stages of pregnancy, it is normal if a pregnant woman experiences nausea and vomiting at night. This condition belongs to early pregnancy reaction, and many women will have this symptom. Early pregnancy reactions occur mainly due to the increase of chorionic gonadotropin level in the body of pregnant women, and are also related to poor rest, poor mental state and poor physical condition of pregnant women. Usually, early pregnancy reactions will start to appear in one month or so, and the symptoms will be relieved slowly from two and a half months. It is recommended to pay attention to rest, eat lightly and get enough sleep in the early pregnancy.