It is normal to experience a slight tingling or swelling sensation in the breasts after pregnancy. This is because the placenta secretes hormones after pregnancy, which will cause the areola and nipple to widen and deepen in color, and also cause the milk ducts to expand and produce milk, which will cause a slight tingling sensation during this period. However, if the breast swelling and pain are more obvious during pregnancy, or if there is a hard lump in the breast, it is considered to be caused by breast enlargement or lobular hyperplasia. If the condition is not serious, medication is not recommended during breastfeeding to avoid affecting the health and growth of the fetus. However, if the condition is particularly serious and the pain is particularly severe and affects normal life, treatment must be done under the guidance of a doctor.