Breast swelling and pain during pregnancy is mainly caused by the increase in hormone levels, resulting in the enlargement of the breasts, which is generally a normal physiological phenomenon and does not require too much worry. The reason for breast swelling and pain is that after pregnancy, estrogen, progesterone, growth hormone and other hormones in the body will increase significantly to meet the needs of breastfeeding during pregnancy and postpartum. Under the action of these hormone levels, can cause breast gland ducts and alveolar hyperplasia, generally the eighth week of pregnancy, the breast will appear significantly larger, women will also appear breast swelling, itching, and women’s nipples, areola will appear pigmentation, nipple erect, areola enlargement, are normal. Pregnant women need to maintain a calm state of mind, avoid excessive tension, usually can choose comfortable and soft underwear or bra, to ensure that the elasticity is appropriate, to avoid the breast or nipple is squeezed, and often wash the breasts, but also can be a hot compress to ease the feeling of swelling and pain. Some pregnant women with breast swelling and pain may also be caused by diseases. It is recommended that if you have obvious breast swelling and pain that cannot be relieved, you should consult a doctor in time to get a clear diagnosis and rule out breast hyperplasia, breast cancer and other diseases.