Breast tissue is naturally lumpy in many women, and lumps often vary with the menstrual cycle. A true lump is a firm, distinct, persistent area that feels different from the surrounding tissue.
Possible causes of a breast lump
- A simple cyst — a fluid-filled sac
- A fibroadenoma — a smooth, elastic, harmless growth
- Fibrocystic breast changes
- An infection or inflammation of breast tissue
- In a minority of cases, cancer
You cannot reliably tell these causes apart by touch. If a lump is new, hard, fixed, growing, or simply lasts more than one menstrual cycle, have it examined with imaging and, if needed, a biopsy.