Physiological vs pathological discharge
Physiological discharge is normal and can occur in response to nipple stimulation, certain medications, or hormonal changes. It is typically milky or clear, affects both nipples, comes from multiple ducts, and is expressed only when the nipple is squeezed rather than occurring spontaneously.
Pathological discharge requires investigation. Features that raise concern are spontaneous discharge (occurring without squeezing), discharge from a single duct opening, blood-stained or clear watery discharge from one breast, and discharge in a woman who is not breastfeeding and has not recently been pregnant. Any discharge in a post-menopausal woman also warrants prompt assessment.
Common causes
- Intraductal papilloma (a small benign growth inside a milk duct) — the most common cause of blood-stained nipple discharge
- Duct ectasia (widening and inflammation of the milk ducts, common around menopause)
- Fibrocystic breast changes
- Breast abscess or mastitis (infection)
- Medications including certain antidepressants, antipsychotics, blood pressure medications, and opioids
- Elevated prolactin levels due to a pituitary gland condition (prolactinoma)
- Ductal carcinoma in situ (DCIS) or invasive breast cancer — less common but must be excluded
- Paget's disease of the nipple
When to see a doctor
- Discharge that occurs on its own without squeezing the nipple
- Discharge from one breast only, or from a single duct opening
- Blood-stained, pink, or clear watery discharge
- Any discharge in a post-menopausal woman
- Discharge accompanied by a lump, skin change, or nipple inversion
- Discharge that has started recently without an obvious cause
How the assessment works
Dr. Shruthi takes a detailed history of the discharge, including how long it has been present, whether it occurs spontaneously or only on squeezing, the colour, and which breast is affected. A clinical breast examination follows. Depending on the findings, she may arrange targeted imaging and additional tests.
- Breast ultrasound to assess the ducts and identify any intraductal lesions or masses
- Mammogram where clinically appropriate, particularly in women over 40
- Ductogram (galactogram) to visualise the duct architecture when a papilloma is suspected
- Cytology of the discharge fluid in selected cases
- Blood tests to check prolactin and thyroid hormone levels if a hormonal cause is suspected
Treatment options
Observation and reassurance: When the discharge is physiological and no structural cause is found, reassurance and watchful monitoring are appropriate. Avoiding nipple stimulation often reduces or stops physiological discharge over time.
Medical management: If an elevated prolactin level or thyroid imbalance is identified, medication to address the hormonal cause usually resolves the discharge. Medications that are causing the discharge may be reviewed with the prescribing doctor and adjusted where possible.
Microdochectomy: When an intraductal papilloma is identified as the source of persistent or blood-stained discharge, surgical removal of the affected duct (microdochectomy) is the standard treatment. The procedure is performed under general anaesthesia and removes the responsible duct through a small incision at the areola edge. It preserves the surrounding breast tissue and ducts.
Total duct excision: For women with discharge from multiple ducts, often related to duct ectasia, removal of all the major ducts behind the nipple (Hadfield's procedure) may be recommended. This is also the appropriate procedure for women who have completed their family and do not wish to preserve breastfeeding capability.
Blood-stained nipple discharge should always be assessed, but the most common cause is an intraductal papilloma, which is benign. Getting it checked promptly means the right diagnosis sooner and, in the majority of cases, genuine reassurance.