What Causes Nipple Discharge? How Can It Be Treated?

Nipple discharge primarily occurs due to benign papillomas in the milk ducts, ductal ectasia (duct dilation), hormonal imbalances, or side effects of certain medications. Although it may rarely be seen as a sign of early-stage breast cancer, how this condition resolves depends entirely on the underlying cause; medical treatment is applied for hormonal problems such as elevated prolactin, while surgical methods such as microdochectomy are used for intraductal mechanical lesions, allowing the discharge to be treated permanently. Physiological discharges usually begin to resolve on their own when the nipple is not squeezed and mechanical stimulation is stopped.

What Causes Nipple Discharge and How Common Is This Condition?

You can think of breast tissue as a huge and complex factory whose primary function is to produce fluid. By its nature, this tissue is a gland. Just as our eyes can water or our mouths can produce saliva, the secretion of fluid by breast tissue during certain periods and in response to certain stimuli can be considered physiological, meaning part of the body’s natural functioning.

This condition is much more common than you may think. Approximately 5% to 10% of women experience nipple discharge at some point in their lives. Around 7% of patients who apply to general surgery outpatient clinics are women presenting solely with this complaint. The most important task for us, and of course for you, is to distinguish whether this discharge is an “innocent” process or a “pathological” condition requiring treatment. This is because while a significant proportion of benign breast diseases present with discharge, sometimes these fluids may also be the first and only sign of disorders that progress silently.

Which Type of Nipple Discharge Is Dangerous and What Is a “Red Flag”?

As physicians, when listening to a patient, we divide the discharge into two main categories in our minds: Physiological discharges and Pathological discharges. Physiological discharges usually develop due to hormonal fluctuations in the body or excessive stimulation of the breast (squeezing). They generally come from both breasts and emerge from more than one opening on the nipple. However, discharges we describe as “pathological” and that raise surgical concern are different.

Some characteristics that we describe as “red flags” in medical evaluation include:

• Discharge coming from only one breast
• Fluid coming out spontaneously
• Discharge emerging from a single duct opening
• Bloody discharge
• Presence of a breast lump
• Swelling in the armpit

If the discharge stains your underwear or nightgown spontaneously without any squeezing, this is one of the most important warning signs for us. In addition, discharge originating from only one breast and from a single point on that nipple indicates that the problem may be located within that specific milk duct rather than being caused by a general hormonal imbalance.

What Does the Color of the Discharge Tell Us About Nipple Discharge?

The color and consistency of the fluid coming from the nipple provide us with very valuable clues about what may be happening inside. Patients often become extremely frightened by the color they see; however, not every color has as serious a meaning as you may think. As physicians, we analyze the character of the discharge and eliminate possible causes in our minds.

The discharge colors we may encounter include:

• Blood red
• Pink
• Clear like water
• Milky white
• Green
• Brown
• Black
• Yellow and purulent

Bloody or pink-colored (serosanguineous) discharges are the group we take most seriously. This color indicates that a tissue located within the milk duct is bleeding. Although it is usually seen in benign formations called “papillomas,” it is the condition that requires the greatest caution in terms of cancer risk. Clear and transparent discharges like water are similarly highly important because early-stage cancers may sometimes reveal themselves only through leakage of clear fluid.

On the other hand, although green, khaki, brown, or black discharges often cause great panic in patients, medically they are more commonly associated with benign causes. These colors indicate fluids that have remained in the duct for a long time, oxidized, and become concentrated. Milky white discharges usually indicate a hormonal condition rather than a problem originating from the breast tissue itself.

What Is an Intraductal Papilloma and Why Does It Cause Nipple Discharge?

In approximately 60% to 70% of patients who come to the outpatient clinic with bloody or suspicious discharge, tests reveal an “Intraductal Papilloma.” This is the most common cause of pathological discharge. Intraductal papillomas are small cauliflower-like or wart-like structures that arise from the cells lining the inner surface of the milk ducts and attach to the duct wall through a thin vascular stalk.

The main reason these formations cause nipple discharge is that they are very fragile. Their structure is so delicate that they may bleed with the slightest trauma inside the duct or even spontaneously. This bleeding travels along the duct and exits through the nipple. Papillomas are technically benign tumors. However, some papillomas may contain irregular (atypical) cells around them or may conceal a very small cancer focus that has not yet formed a lump. For this reason, when we identify a papilloma causing bloody discharge, our approach is generally to remove it surgically.

Is Ductal Ectasia a Cause of Nipple Discharge?

Another benign condition we frequently encounter, especially in women approaching menopause or in the perimenopausal period, is “Ductal Ectasia.” With advancing age or under the influence of environmental factors such as long-term smoking, the main milk ducts located just behind the nipple undergo structural changes.

These changes include:

• Dilation of the ducts
• Shortening of the duct length
• Thickening of the walls
• Fluid accumulation inside

Cellular debris and fatty materials accumulate inside these dilated ducts. Over time, this buildup becomes thick and paste-like. This is usually the cause of green, black, or dark brown discharge. If this dense content leaks outside the duct, it may initiate a sterile inflammation within the breast tissue called plasma cell mastitis. This condition can sometimes cause inward retraction of the nipple and be confused with cancer, but it is actually a benign aging process.

Which Medications Cause Nipple Discharge?

Sometimes the source of the problem may not be the breast but a medication you are taking or another imbalance in your body. The pituitary gland in our brain secretes the hormone “prolactin,” which enables milk production. Under normal conditions, the level of this hormone is suppressed and controlled by a substance called dopamine. However, some medications that reduce dopamine levels or block its effect cause the prolactin hormone to rise. As a result, milk may come from your breasts even though you are not breastfeeding; we call this condition “galactorrhea.”

Medication groups that may increase prolactin levels and cause discharge include:

• Antidepressants
• Antipsychotics
• Blood pressure medications
• Stomach medications
• Birth control pills

The discharge seen in patients using these medications usually comes from both breasts and is milky in color. In such a situation, you should definitely consult your doctor instead of stopping the medication; adjusting or changing the dosage usually resolves the problem.

Can Nipple Discharge Be a Sign of Cancer?

This is the question our patients are most hesitant to ask but most eager to have answered. To be open and honest: Yes, it can. However, do not panic immediately. According to statistics, breast cancer is detected in approximately 9% to 20% of patients with pathological discharge that is unilateral and spontaneous. This rate increases especially in patients over the age of 40 and when there is a palpable lump accompanying the discharge.

Ductal Carcinoma In Situ (DCIS), the earliest form of breast cancer that we call “Stage 0,” may sometimes reveal itself through bloody or clear discharge while remaining confined within the milk duct without forming any lump. In addition, a special type called “Paget’s Disease” progresses with eczema-like, non-healing sores and crusting on the nipple. Therefore, not every discharge is cancer, but every discharge should be examined seriously to definitively rule out the possibility of cancer. Early diagnosis is life-saving in breast cancer, and discharge may be an early signal given by the body.

How Is Nipple Discharge Evaluated During a Doctor’s Examination?

When you consult a general surgery specialist, the process begins with a detailed conversation. The duration and color of the discharge, its relationship with the menstrual cycle, and the medications you use are very important to us. This is followed by a physical examination. Our aim here is not only to see the discharge but also to determine where it is coming from.

The points your doctor will check during the examination include:

• Structure of the breast tissue
• Presence of a lump
• Axillary lymph nodes
• Trigger point
• Number of ducts from which the discharge comes

Identifying the trigger point is very valuable to us. By gently applying pressure around the nipple in the direction of a clock face, we try to determine from which position and which duct the discharge originates. This is vital for subsequent surgical planning. At this stage, my most important warning to patients is this: Do not squeeze your breast in the days before the examination to check whether there is discharge. That one drop of fluid accumulated in the duct is the most valuable clue that may allow us to make the diagnosis; do not waste it at home.

Which Methods Are Used to Diagnose Nipple Discharge?

We use radiological imaging methods during the diagnostic process. However, when nipple discharge is involved, conventional methods such as ultrasound and mammography have certain limitations. This is because we are looking for intraductal problems measuring only a few millimeters, and these methods may sometimes be insufficient to show such small details.

The imaging methods we frequently use include:

• Breast Ultrasonography
• Mammography
• Breast MRI (Magnetic Resonance Imaging)
• Ductoscopy

Ultrasound is the first choice especially in women under the age of 35; it can show dilated ducts, but its success rate in detecting small papillomas is around 60%. Mammography is always performed in women over the age of 35-40; it detects cancer foci that present with calcification, but its sensitivity in finding the cause of discharge may remain as low as 42%. MRI is more sensitive, but it also cannot always make a definitive distinction. Unfortunately, sending a sample of the discharge to the laboratory for cytology may also frequently produce a “false negative” result, meaning it may appear normal even when cancer is present. Therefore, we need more advanced technologies for diagnosis.

How Is Nipple Discharge Diagnosed with Ductoscopy?

At this point, “Ductoscopy,” one of the greatest opportunities modern surgery offers us, comes into play. Just as endoscopy is performed to look inside the stomach with a camera for stomach complaints, ductoscopy is the procedure of entering and examining the milk ducts with microcameras. Over the last twenty years, this method has become the “gold standard” in the management of nipple discharge.

While ultrasound or mammography provides us with external shadows and silhouettes, ductoscopy gives the surgeon the chance to see the inside of the milk duct directly, in color, and magnified on a monitor. The diameter of the milk ducts is around 1-2 millimeters, while the microendoscopes we use are thinner than 0.5 millimeters. Thanks to this technology, millimetric papillomas or very early cancerous changes that cannot be seen with other methods can be detected with a very high accuracy rate of approximately 93%. This method, which is also successfully applied in Türkiye, prevents unnecessary major operations while also preventing cancer from being overlooked.

What Is Done During a Ductoscopy Procedure?

Ductoscopy is not a procedure patients need to fear. It is generally a very comfortable procedure that does not require operating room conditions and can be performed in an office setting or procedure room. General anesthesia is not needed during the procedure; only the nipple is numbed.

The stages of the procedure are as follows:

• Cleaning the nipple
• Applying local anesthesia
• Dilating the duct opening
• Inserting the microcamera
• Expanding the duct with saline
• Examining the inner surface

The procedure takes approximately 20 to 45 minutes. After entering through the tiny opening from which the discharge comes, saline solution is administered to inflate the duct, which resembles a deflated balloon. The camera is advanced into the depths of the duct, approximately 4-5 cm and sometimes up to 9-10 cm, and the duct system branching like tree limbs is examined. After the procedure is completed, the patient can immediately return to daily life.

Is Medical Treatment Possible for Nipple Discharge?

Treatment for nipple discharge is shaped entirely according to the underlying cause. Not every patient requires surgery. First, the cause of the discharge is clarified. If the problem is hormonal or related to infection, medical treatments are prioritized.

Medical treatment options include:

• Dopamine agonists
• Antibiotics
• Anti-inflammatory medications

For example, if blood tests show that your prolactin hormone level is high and this is due to an adenoma in the pituitary gland, you are generally treated with medications such as “Cabergoline” or “Bromocriptine” without requiring surgery. These medications lower the prolactin level and stop milk production. If the discharge is foul-smelling and purulent due to mastitis, the infection is treated with appropriate antibiotic therapy.

What Are Nipple Discharge Surgery and Surgical Methods?

If the cause of the discharge is a mechanical obstruction such as a papilloma, a suspicious lesion, or a precancerous condition, the treatment is surgical. However, the surgical methods we use today are highly “minimally invasive,” meaning techniques that cause the least possible tissue damage.

The main surgical methods applied include:

• Microdochectomy
• Hadfield Procedure
• Endoscopic Excision

I would particularly like to emphasize “Microdochectomy.” This method involves removing the diseased duct whose location has been precisely identified through ductoscopy. A small crescent-shaped incision is made at the edge of the colored part of the nipple. The diseased area, which is marked internally with a thread or wire during ductoscopy, is located with pinpoint accuracy and removed. The greatest advantage of this method is that only the diseased duct is removed while the other healthy milk ducts are left untouched. In this way, the woman’s ability to breastfeed is preserved. In older patients or in cases involving multiple ducts, the “Hadfield” procedure, in which all ducts are removed, may be preferred.

What Is the Recovery Process Like After Surgery?

One of the issues our patients are most concerned about is the postoperative process. However, procedures such as microdochectomy performed for nipple discharge are generally classified as “day surgery.” In other words, you can have surgery in the morning and drink your tea at home in the evening.

The characteristics of the recovery process include:

• Minimal pain
• Rapid discharge
• Hidden surgical scar
• Quick return to daily life

Because the incision is hidden along the line where the brown part of the nipple, called the areola, meets the normal skin, it is very difficult to notice from the outside once healing is complete. The sutures are generally cosmetic and placed under the skin, so there is no need to have stitches removed. You can comfortably return to work and social life within a few days.

What Are the Recommendations for People with Nipple Discharge?

Some mistakes patients make while dealing with nipple discharge may prolong the process or make diagnosis more difficult. Being informed about this issue is very important for both your psychological well-being and your treatment process.

Some points you should pay attention to include:

• Not squeezing the nipple
• Noting the color of the discharge
• Informing the doctor about medications
• Having regular check-ups
• Not panicking