Most women experience breast changes at some time. Your age, hormone levels, and medicines you take may cause lumps, bumps, and discharges (fluids that are not breast milk).
If you have a breast lump, pain, discharge or skin irritation, see your health care provider. Minor and serious breast problems have similar symptoms. Although many women fear cancer, most breast problems are not cancer.
Some common breast changes are
Fibrocystic breast changes - lumpiness, thickening and swelling, often just before a woman's period
Cysts - fluid-filled lumps
Fibroadenomas - solid, round, rubbery lumps that move easily when pushed, occurring most in younger women
Intraductal papillomas - growths similar to warts near the nipple
Blocked milk ducts
Milk production when a woman is not breastfeeding
NIH: National Cancer Institute