Breast swelling and pain in early pregnancy is a normal maternal change in early pregnancy. When the hormone level in the mother’s body is stable, the breast will gradually adapt and the swelling and pain will gradually be relieved, and most pregnant women will disappear in about 2-3 months of pregnancy. After pregnancy, due to the influence of large amounts of estrogen (stimulating the development of breast ducts) and progesterone (stimulating the development of breast alveoli) secreted by the placenta, breasts start to increase in size in early pregnancy and become engorged with blood; pregnant women feel that their breasts are swollen, which is a common manifestation of early pregnancy. The enlarged nipples become darker and more easily erect, the surrounding areolas deepen in color, and the peripheral sebaceous glands hypertrophy to form scattered nodular elevations, Montgomery’s nodes. Breast swelling and pain in early pregnancy usually does not require special treatment, and hot compresses can be applied if necessary. It should be noted that if the breast swelling and pain are getting heavier and heavier, or if the swelling and pain have not been reduced after early pregnancy, the pathological conditions of the breast, such as breast fibroid hyperplasia and breast cancer, can be excluded. If necessary, ultrasound examination of both breasts should be performed to exclude pathological conditions. In conclusion, breast pain in early pregnancy mostly disappears around 2-3 months of pregnancy, if it does not ease or even gradually worsen after the expiration date, we need to be alert to pathological conditions and seek medical attention in time.