Most of the swollen feet during pregnancy are caused by physiological reasons, while a few are caused by pathological reasons. Physiological causes include changes in hormone levels and enlargement of the uterus, while pathological causes include kidney and heart diseases, hypertension and hypoproteinemia during pregnancy. 1. Physiological causes: (1) Changes in hormone levels: hormone levels increase rapidly after pregnancy, increasing the reabsorption of sodium in the renal tubules, and there will be water and sodium retention in the middle and late stages of pregnancy, with edema at the ankles. (2) Enlargement of the uterus: With the growth and development of the fetus after pregnancy, the enlarged uterus will compress the inferior vena cava of the pregnant woman, and the blood circulation of the lower limbs will be affected, which will easily cause swelling of the feet. Physiological causes of swollen feet, the next morning the symptoms will disappear on their own. 2. Pathologic causes: (1) Abnormalities in the heart and kidneys of pregnant women: If the heart and kidneys of pregnant women have diseases during pregnancy, it will lead to swollen feet. In serious cases, edema of the face and other parts of the body will occur, and will be accompanied by panic and shortness of breath, dyspnea and other conditions. (2) High blood pressure during pregnancy: High blood pressure during pregnancy can cause edema and proteinuria. (3) Hypoproteinemia: Some pregnant women have poor physical condition and are severely picky about food during pregnancy, causing malnutrition, which can lead to hypoproteinemia, swollen feet and weakness. Swollen feet caused by physiological reasons have no effect on the health of pregnant women. Pathological causes of swollen feet not only affect the health of pregnant women, but may also affect the growth and development of the fetus. Go to the hospital in time, do the relevant examination under the doctor’s advice, and take the appropriate treatment and adjustment measures.