The swelling and pain of the breast during pregnancy is due to the increase in the level of hormones in the body and the swelling and pain caused by the development of the breast. As the pregnancy week increases the hormone level in the body affects the breast gland gradually increases, so as to make adequate preparation for breastfeeding during the postpartum period, this kind of swelling and pain symptoms are relatively light and generally tolerable, pay attention to maintain a happy mood. The more common ones are cystic hyperplasia of the breast, which has already had symptoms of breast hyperplasia before pregnancy, and the symptoms of breast hyperplasia are aggravated by pregnancy, so you can go to the hospital for ultrasound to confirm the diagnosis. After impact trauma to the breast, localized pain and discomfort may also occur, and it is not difficult to diagnose with a clear history of previous trauma. In addition, inflammation of the nipple, tuberculosis of the breast and other chronic inflammatory diseases can also cause local swelling and pain, so try to go to the hospital for examination and diagnosis.