Jul 9, - Around 70 percent of women report pain in one or both breasts, and only about 15 percent require treatment. It is common in women who are. The most common hormonal breast soreness comes from an increase in the level of oestrogen before a period. This causes milk ducts and glands to swell, trapping fluid in the breasts. Many women have tenderness or pain in the lead-up to a period, and sometimes right through it.