Does duct ectasia cause nipple discharge?

Duct ectasia is a non-cancerous change in a milk duct behind the nipple. The duct can widen, its walls can thicken, and fluid may build up inside it. This may lead to discharge that is thick, sticky, cloudy, greenish or dark, although appearance alone cannot identify the cause.

Some people also notice nipple tenderness, itching, a turned-in nipple or a small area of swelling near the nipple. Duct ectasia may cause no symptoms at all. Nipple discharge has other possible causes, including hormonal changes, infection, medicines and changes within another duct, so a clinician may examine the breast and decide whether imaging or a sample is needed.

Arrange a breast assessment if the discharge is new, persistent or troublesome. Note whether it comes from one or both breasts, whether it appears without squeezing, and its colour and consistency. Avoid repeatedly checking or expressing the nipple, because handling can keep discharge going and irritate the area. A supportive bra and a warm compress may ease tenderness; do not put creams or antibiotics on the nipple unless advised.

Seek prompt medical advice for bloody or clear discharge from one breast, discharge that happens without touching the nipple, a new lump, a nipple that becomes newly inverted, or skin changes such as dimpling. Contact a clinician quickly if the breast is red, hot, increasingly painful or accompanied by fever, as these features can point to infection. A new discharge deserves assessment even when duct ectasia is one possible explanation.

You could ask: What features of my discharge suggest duct ectasia or another cause? Do I need breast imaging? What changes should make me return sooner? Could any medicine, pregnancy or breastfeeding explain the discharge?