Table: Common Breast Symptoms - Merck Manuals Consumer Version

Common Breast Symptoms

Symptom	Causes	Comments
Breast pain Breast Pain Many women experience breast pain. Breast pain may occur in one or both breasts. (See also Overview of Breast Disorders.) Likely causes of breast pain depend on whether the pain is felt in a... read more	Hormonal changes related to menstrual periods, pregnancy, or use of hormonal drugs Cysts Breast Cysts Breast cysts are fluid-filled sacs that develop in the breast. (See also Overview of Breast Disorders and Breast Lumps.) Breast cysts are common. In some women, cysts develop frequently, sometimes... read more Breast infections Breast Infection and Breast Abscess Breast infections are usually caused by bacteria. Rarely, breast infections lead to a breast abscess (a collection of pus in the breast). Mastitis refers to painful inflammation of the breast... read more * Fibrocystic changes Fibrocystic Changes of the Breast Fibrocystic changes of the breast (formerly called fibrocystic breast disease) include breast pain, cysts, and lumpiness that are not due to cancer. (See also Overview of Breast Disorders and... read more Large breasts that stretch supporting tissues Very rarely, breast cancer Breast Cancer Breast cancer occurs when cells in the breast become abnormal and divide uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes (ducts) that carry... read more	Pain that occurs throughout both breasts is usually caused by hormonal changes related to menstrual periods.
Breast lumps Breast Lumps A breast lump (mass) is a thickening or bump that feels different from surrounding breast tissue. A lump may be discovered by a woman or during a routine physical examination by a doctor. (See... read more	Breast infections, including abscesses* Cysts Fibroadenomas Fibroadenomas of the Breast Fibroadenomas of the breast are small, smooth, solid, rounded noncancerous lumps composed of fibrous and glandular tissue. (See also Overview of Breast Disorders and Breast Lumps.) Fibroadenomas... read more Fibrocystic changes Galactocele (a clogged milk duct) Scar tissue that develops after an injury Breast cancer	Lumps in the breasts are relatively common and are usually not cancerous. Because cancerous and noncancerous lumps are hard to distinguish during a physical examination, tests are usually done.
Nipple discharge Nipple Discharge Fluid that leaks from one or both nipples is called nipple discharge. Each breast has several (15 to 20) milk ducts. A discharge can come from one or more of these ducts. (See also Overview... read more	Most commonly, noncancerous milk duct tumors (intraductal papilloma) Breast cancer Breast infections, including abscesses* Fibrocystic changes Other disorders, such as pituitary, brain, or thyroid disorders) Certain drugs (see table Some Causes and Features of Nipple Discharge )	A nipple discharge occurs normally sometimes—for example, during milk production after childbirth. Abnormal discharges vary in appearance depending on the cause.
* Breast infections are very rare except during the first few weeks after childbirth.