The time of appearance of edema in pregnancy varies greatly among individuals, with pathologic edema appearing around 20 weeks of pregnancy and physiologic edema appearing around 28 weeks in mid- to late-pregnancy. 1. Pathological edema appears earlier after pregnancy, for example, edema caused by gestational hypertension begins to appear around 20 weeks of pregnancy. Accompanied by the patient’s increase in gestational weeks, if the blood pressure can not be controlled, the edema of pregnant women will become more and more serious, and may even appear in the pleural fluid, ascites, etc., this situation requires active intervention with drugs. 2. Physiological edema usually occurs more in the afternoon or late afternoon, and begins to appear in the middle and late stages of pregnancy around 28 weeks. Simple edema is due to the increased fetal compression of venous return in the lower extremities, the need for moderate exercise or massage of the lower extremities or elevation of the feet to improve edema, and dietary restrictions on salt intake, eat light and nutritious food.