The time of early pregnancy reaction varies from person to person, most women gradually appear after 6 weeks of menopause, and a few pregnant women can appear at about 5 weeks of menopause. The causes of early pregnancy reaction are mainly related to the increase of human chorionic gonadotropin level in the body, the decrease of gastric acid secretion and the decrease of gastric emptying function. The main symptoms are coldness and fear of cold, salivation, drowsiness, weakness, lack of appetite, preference for acidic food, aversion to greasy food, morning sickness and so on. Breast changes can start to appear at 8 weeks of pregnancy, including gradual growth of breasts, enlargement of nipples, deepening of nipple and areola coloring, and the appearance of brown nodules around them. Most of the early reactions of pregnant women will disappear by themselves around 12 weeks of pregnancy. Generally, there is no need to deal with mild early pregnancy reactions, pregnant women should pay attention to more rest, arrange life and rest reasonably and keep indoor air circulation.