This condition is commonly seen in the formation of parametrial breasts, as people normally have two breasts, and some other breasts degenerate during the evolutionary process. When the hormone level in the body increases, it will cause these degenerated breasts to proliferate again and a lump-like pain will appear in the armpit, and sometimes even milk will be secreted, which is usually nothing to worry too much about. The lumps can gradually subside as time goes on. If the pain is still localized after childbirth, you need to check the ultrasound further and send the lump for pathological biopsy if necessary, and apply some ointment locally to reduce the pain.