After pregnancy, in order to adapt to the growth and development of the fetus and delivery, a series of physiological changes will occur in various organs and systems of pregnant women, which can be called pregnancy reactions, mainly in the following aspects: 1. Early pregnancy reactions: the most common pregnancy reactions, mostly caused by changes in hormone levels in women’s bodies after pregnancy, such as cold, dizziness, weakness of limbs, drowsiness, decreased appetite, hate greasy, like to eat sour food, nausea, morning vomiting, etc. 2. Frequent urination: it often occurs in the first 3 months and the last 3 months of pregnancy. In the early stage of pregnancy, due to the enlarged uterus pressing the bladder, frequent urination occurs; after 12 weeks of pregnancy, the uterus crosses out of the pelvis into the abdominal cavity, and the symptoms of frequent urination can disappear naturally; in the last three months of pregnancy, due to the entry of the fetal dew into the pelvis, the bladder is squeezed again, and the symptoms of frequent urination will appear again. 3, breast swelling and pain: after pregnancy, pregnant women can secrete a large amount of estrogen and progesterone, which promotes the development of breast alveoli and ducts, therefore, the breasts will gradually increase in size after pregnancy, congestion is obvious, the common symptoms are itching, tingling, swelling and other manifestations of breast enlargement, while the nipples increase in size and become black, easy to erect, the surrounding areola color deepens, nipple tingling. 4, constipation, flatulence: after pregnancy, the influence of progesterone, gastric acid secretion decreased, the gastrointestinal tract peristalsis slowed down, the gastric emptying time extended, coupled with eating, drinking and outdoor activities during pregnancy to reduce the amount of pregnant women easily caused by indigestion, constipation, flatulence and other symptoms. 5, edema: mostly occurs in late pregnancy, due to the gradually increasing uterus compression of the lower limb veins, so that the lower limb blood return is blocked, the lower limb venous cavity pressure increases, easy to appear lower limb edema, more obvious in the afternoon, after rest and elevation of the affected limb improved. 6, low back pain and sciatica: with the gradual increase of the uterus, the pregnant woman’s body weight unconsciously shifts forward, resulting in increased burden on the muscles and ligaments of the waist and back, and small joint dislocation of the spine, which compresses the sciatic nerve and causes pain. In addition, overexertion, tension, prolonged standing, bending or lifting heavy objects are also causes of low back pain. In summary, the hormonal changes in pregnant women’s bodies and the enlargement of the pregnant uterus can cause a number of pregnancy reactions during pregnancy. Pregnant women need to maintain a good mood during pregnancy, pay attention to rest, avoid straining and heavy physical labor, and seek medical attention when discomfort occurs.