Nipple discharge: should you be worried?
A fluid — clear, milky, coloured, sometimes bloodstained — is leaking from your nipple? It is a common reason for worry, and most often harmless. But certain features should prompt a quick check. Here is how to tell an ordinary discharge from one to investigate, what the colour means, the possible causes and the work-up.
If a fluid comes on its own, affects only one breast, comes from a single pore (especially if bloodstained), or comes with a lump, an examination is recommended. Dr Zeitoun, breast surgeon, sees patients at the practice (Paris 8e) and at Clinique Hartmann (Neuilly).
Written and reviewed by Dr Jérémie Zeitoun, breast surgical oncologist · Nipple discharge means the release of fluid from the nipple, outside pregnancy and breastfeeding. It is a common situation and, contrary to the worry it often causes, the great majority of discharges are benign. Cancer is a rare cause of discharge.
To know whether a discharge should be investigated, what matters is not so much how much there is, but its features: does it come on its own (spontaneous) or only when you press (provoked)? Does it affect one breast or both? Does it come from a single pore of the nipple or from several? What colour is it? Is there an associated lump?
This article explains how to tell a benign discharge from a suspicious one that calls for a surgical opinion, what the colour means, the possible causes — first among them the intraductal papilloma —, how the work-up unfolds (ultrasound, mammogram) and, when it is useful, surgery.
A discharge to have assessed?
Characterising the discharge, imaging work-up, a second opinion on what to do next: a direct consultation with the breast surgeon.
Understanding nipple discharge
The breast is criss-crossed by fine ducts, the milk (lactiferous) ducts, which converge towards the nipple. It is through them that milk flows during breastfeeding — and it is also through them that fluid can come out at other times. Discharge is therefore not an abnormality in itself: everything depends on its features.
Where does the fluid come from?
Behind the nipple, around a dozen milk ducts open through as many tiny pores. Fluid coming from a single pore points to a cause located in one duct (for example a papilloma). Fluid coming from several pores, on both sides, points instead to a hormonal or benign cause, to be confirmed by a work-up.
This is why the first step is not to be alarmed by the amount, but to observe how the discharge happens.
Provoked or spontaneous: the first question
A provoked discharge appears only when the nipple is squeezed. Provoked does not mean harmless: a discharge that persists, even if you have to press to see it, should be reported and investigated with a full work-up.
A spontaneous discharge, by contrast, comes on its own: it stains the bra or top without being touched. It is the feature that should raise the most concern.
One side or both? One pore or several?
These two simple questions, on their own, guide much of the reasoning.
Benign or suspicious: who to see?
Whatever it looks like, a persistent discharge means you should see a doctor: even bilateral or seemingly "harmless", it warrants a full work-up (clinical, biological and hormonal, imaging) to establish the diagnosis. You always consult — but not always the surgeon. What changes is who to see: a benign pattern is managed with the gynaecologist or midwife; a suspicious pattern calls for a surgical opinion.
When in doubt, see a doctor
A discharge that worries you always deserves an opinion. Your GP, gynaecologist or midwife make the first assessment; the surgeon steps in for suspicious patterns.
Refer to the gynaecologist or midwife
Discharge from both sides, from several pores, milky or clear serous, with no lump or nipple change, in a suggestive context (medications, post-partum). Most often a benign profile — but you still see a doctor: a full work-up (clinical, biological and hormonal, imaging) confirms the diagnosis and looks for other benign causes (fibrocystic changes, duct ectasia…). To be arranged with your gynaecologist or midwife. Benign breast conditions →
Surgical opinion recommended
See the surgeon in case of: diagnostic doubt, an imaging abnormality (a lesion, a high BI-RADS / ACR category), real day-to-day bother, or a bloodstained discharge. Also suggestive: a spontaneous discharge, from one side only, from a single pore, clear "like water", with a lump or a nipple/skin change, or appearing after the menopause.
Worth remembering. No persistent discharge should be ignored — you always see a doctor, even if bilateral or ordinary-looking. The surgeon is needed in case of doubt, an imaging abnormality, real bother, or a bloodstained discharge; other patterns are handled with a work-up by the gynaecologist or midwife.
What the colour means
The colour points towards a cause, without ever proving it. It is always read alongside the other features (spontaneous or not, one side or both, one pore or several).
Milky discharge
Often from both sides, from several pores, outside pregnancy: this is galactorrhoea, most often hormonal in origin (medications, prolactin, thyroid). Management is usually medical.
Thick, coloured discharge
Green, brown or "multicoloured", thick, from both sides: most often suggests duct ectasia — a benign widening of the ducts, common around the menopause. Usually just monitoring.
"Watery clear" discharge
A clear, transparent fluid, like water: it can be benign, but if it is spontaneous and from a single pore, it is among the discharges to investigate, just like a bloodstained one.
Blood-tinged discharge
Red or pink: should always be investigated. The most common cause remains benign — often an intraductal papilloma. Cancer is a rare cause.
Note. A green or brown discharge is not "old" blood and is no more worrying than a clear one. Conversely, a clear discharge is not necessarily harmless. It is always the combination of features, not the colour alone, that decides.
The causes of a discharge
Several causes can explain a discharge. Most are benign. Here they are, from the most common to the rarest.
Imaging looks for the origin
Behind a discharge, we look for a precise cause: papilloma, duct ectasia, fibrocystic changes… The clinical exam and imaging, read by the radiologist, guide the diagnosis.
Intraductal papilloma
A small benign growth inside a duct, just behind the nipple. It is the most common cause of a spontaneous, bloodstained, single-pore discharge. It is an "at-risk" lesion that warrants vigilance and, often, removal for analysis. Everything about the papilloma →
Duct ectasia
A benign widening of the ducts behind the nipple. It gives a discharge that is often thick, green or brown, from both sides. It is a commonplace situation that usually needs only monitoring.
Galactorrhoea
A milky, bilateral discharge linked to a hormonal imbalance: certain medications, a high prolactin level, a thyroid problem. Management is medical (blood test, sometimes an endocrinology opinion), not surgical.
Fibrocystic changes
The very common benign changes of the breast tissue can come with a provoked discharge, often from both sides. Benign breast conditions →
A duct infection
A mastitis or an abscess can cause a discharge, usually with redness, warmth and pain. Management combines medical treatment and, sometimes, drainage.
A cancerous cause
Cancer is a rare cause of discharge. It may be a cancer starting within a duct, or Paget disease (a change in the nipple skin: redness, crusting, persistent eczema). It is to rule this out that a suspicious discharge is investigated. Breast cancer: the guide →
What to keep in mind
The great majority of discharges have a benign cause — papilloma, duct ectasia, galactorrhoea. Cancer remains a rare cause. The aim of the work-up is not to "hunt for a cancer" at all costs, but to identify the cause of the discharge so as to treat it and, along the way, rule out what needs ruling out.
Intraductal papilloma
The lesion most often behind a spontaneous, bloodstained discharge: a benign "at-risk" growth inside a duct. Diagnosis and management — core biopsy, monitoring, vacuum-assisted excision or microdochectomy.
A discharge that won't settle?
A full work-up (clinical, biological and hormonal, imaging) and advice on where to go — gynaecologist, midwife or surgeon: a consultation with Dr Zeitoun, breast surgeon.
The work-up for a discharge
Any persistent discharge warrants a full aetiological work-up: clinical, biological and hormonal, and imaging. The aim is to identify the cause and rule out a lesion that would call for surgery.
Ultrasound first
Painless and without X-rays, ultrasound is often the first test in the work-up. It looks for a lesion behind the discharge and clarifies its nature, alongside the clinical examination.
The core biopsy, by the radiologist
When a lesion is identified, a sample is taken by the radiologist under ultrasound guidance, with a small clip placed to mark the target. A precise, quick procedure.
Sometimes MRI or galactography
In some isolated discharges with no cause found, a breast MRI or a galactography pinpoints the duct involved. These tests are never routine.
The clinical examination
A focused history (discharge spontaneous or provoked, one side or both, one pore or several, its colour, your medications) and a palpation of the breasts and armpits, with inspection of the nipple. This step already strongly guides the diagnosis.
The biological and hormonal work-up
A blood test looks for a hormonal cause: prolactin and TSH (thyroid) levels, and a review of your medications. Essential for a milky or bilateral discharge, it often forms part of gynaecological follow-up.
Imaging
A breast ultrasound and, depending on age, a mammogram. They look for a lesion and grade it on the BI-RADS (ACR) scale: ACR 1-2 normal or benign, ACR 3 probably benign (monitoring), ACR 4-5 suspicious (sampling). Ultrasound → · Mammogram → · Understand BI-RADS / ACR →
Targeted tests
When the discharge is isolated with no visible abnormality, a galactography (opacification of the duct) or a breast MRI may be offered to locate the cause.
The biopsy
If imaging identifies a lesion, a core needle biopsy is performed by the radiologist in our network, under ultrasound guidance, with a small clip placed to mark the target. Laboratory analysis clarifies the exact nature. Understanding the analysis →
A practical tip. Avoid squeezing the nipple repeatedly to "check": this keeps the discharge going and can hinder the examination. Simply note its features (spontaneous or not, colour, side) to discuss in consultation.
When is surgery needed?
Many discharges do not call for surgery: a hormonal cause (galactorrhoea) is treated medically, and a benign pattern is followed with the gynaecologist or midwife. Surgery addresses two situations: a suspected lesion (spontaneous, unilateral, single-pore, bloodstained discharge, an imaging abnormality, or an identified papilloma); or a discharge that is troublesome in daily life whose exhaustive aetiological work-up (clinical, biological, hormonal, imaging) has remained negative.
Microdochectomy
Also called duct excision, it is the reference procedure for a pathological single-pore discharge. It involves isolating the responsible duct and removing it, together with the lesion that is causing it (often a papilloma), through a small incision around the areola.
It is carried out as a day case, leaves a discreet periareolar scar, and the specimen is always analysed in the laboratory.
What surgery achieves
When a lesion such as a papilloma is responsible, options other than surgery sometimes exist (monitoring, removal by vacuum-assisted excision): they are detailed on the dedicated page. See the management of papilloma →
A suspicious or bloodstained discharge: let's talk it through
Doubt, an imaging abnormality, day-to-day bother or a bloodstained discharge: Dr Zeitoun sees you for a surgical opinion and, if needed, a day-case microdochectomy.
Frequently asked questions
The questions that come up most often about nipple discharge. If yours is not here, ask it at your appointment — or to Sophie, the site assistant, at the bottom right.
Most often it is benign — but never "harmless". Any persistent discharge warrants a full work-up (clinical, biological and hormonal, imaging). What changes is the referral: a benign pattern (both sides, several pores, milky or serous) is managed with the gynaecologist or midwife; a suspicious pattern (spontaneous, one side, a single pore, bloodstained or clear) calls for a surgical opinion.
See a doctor promptly if the discharge is spontaneous (it comes on its own and stains your clothes), if it affects only one breast, if it comes from a single pore, if it is bloodstained, pink or clear, if it comes with a lump or a change in the nipple or skin, if it appears after the menopause, or if there is an imaging abnormality (a lesion, a high BI-RADS / ACR category). These features do not mean "cancer" — they mean "to be examined".
Rarely. A bloodstained discharge should always be investigated, but its most common cause is benign: most often an intraductal papilloma. Cancer is a rare cause. A work-up is done precisely to rule it out and to treat the cause.
A milky discharge, often from both sides, outside pregnancy, is called galactorrhoea. It is usually hormonal in origin (certain medications, a high prolactin level, a thyroid problem). Management is most often medical — a blood test, sometimes an endocrinology opinion — rather than surgical.
A thick, green, brown or multicoloured discharge, often from both sides, most often suggests duct ectasia: a benign widening of the ducts behind the nipple, very common around the menopause. It is a benign situation that usually needs only monitoring.
A full work-up: consultation (history, clinical examination), a biological and hormonal work-up (prolactin, TSH, medication review), a breast ultrasound and, depending on age, a mammogram. In some cases of isolated discharge, a galactography or an MRI. If a lesion is found, a core needle biopsy is performed by the radiologist, with a clip placed.
No. A hormonal cause (galactorrhoea) is treated medically, and a benign pattern is followed with the gynaecologist or midwife. Surgery (microdochectomy, as a day case) addresses two situations: a suspected lesion (spontaneous, unilateral, single-pore, bloodstained discharge, or an identified papilloma); or a discharge that is troublesome in daily life whose exhaustive aetiological work-up has remained negative.
Further reading
To go further on the most common cause of a discharge and on the breast work-up.
Intraductal papilloma
The most common cause of a bloodstained discharge: definition, risk, core biopsy, monitoring, vacuum excision or surgery (duct excision).
Another signA lump in the breast
What to do about a breast lump: what is reassuring, what should prompt a check, and how the work-up unfolds.
ImagingUnderstanding breast ultrasound
Often the first imaging test in the work-up of a discharge: how it works, why it is used, what it shows.
LibraryAll patient articles
Patient guides on breast surgery, gynaecological surgery and intimate surgery — the full library.
A nipple discharge to have assessed?
If a fluid leaks spontaneously, from one side only, from a single pore — especially if it is bloodstained — or with a lump, Dr Jérémie Zeitoun, breast surgeon, sees patients at the practice in the 8th arrondissement of Paris and at Clinique Hartmann in Neuilly-sur-Seine to take stock, calmly and precisely.