The most common reason for having lumps and pain in the armpits before menstruation is due to paratesticular breasts. There are breast tissues in the armpits, which will change according to the endocrine secretion. Before menstruation, the secretion of estrogen in the body is relatively high, while the secretion of progesterone is relatively low, which will lead to localized changes in the mammary glands. If there are breast tissues in the armpits, there will be corresponding changes, and it is recommended to do the corresponding examination to make a clear diagnosis. If the localized breast tissue is detected by color ultrasonography, corresponding surgery can be done clinically, preferably 3-7 days after the menstrual period has been completely cleared, and the localized care can be strengthened after the surgery.