When to worry about nipple discharge if you have breast cancer

Discharge can come from changes within a milk duct, treatment effects, infection, or hormone-related activity. Colour and appearance provide clues but cannot establish the cause on their own. Clear, yellow, milky, or bloody fluid may need different evaluation, especially when it comes from one breast or one duct.

If you already have Breast Cancer, the clinical team will interpret the discharge alongside your examination, imaging, biopsy results, and current treatment. The discharge does not by itself show whether cancer has changed or spread.

Contact your breast care team when discharge is new, continues without squeezing, stains clothing, or occurs with a lump, nipple inversion, skin change, redness, or pain. Note when it began, which breast is affected, whether it appears without touching the nipple, and its colour. Avoid repeatedly expressing the nipple, because stimulation can maintain discharge and make the pattern harder to assess.

Keep scheduled appointments and take a list of medicines, supplements, and recent procedures. Your clinician may examine the breast and nipple and decide whether further imaging, a sample of fluid, or another test is appropriate.

Seek same-day medical advice for bloody discharge, rapidly increasing swelling, marked redness or warmth, fever, severe pain, or a wound that is draining. Go to urgent care for heavy bleeding, faintness, breathing difficulty, or feeling suddenly very unwell. These signs can reflect infection, bleeding, or another problem that needs prompt attention.

Ask: Could my treatment or medicine be contributing to this discharge? Do I need an examination or imaging sooner? What changes should I record? Who should I contact outside office hours?