Nipple discharge

Nipple discharge means fluid coming from a nipple. It may occur on its own or only when the nipple is squeezed. The fluid can come from one breast or both.

Discharge is often linked to pregnancy, breastfeeding, nipple stimulation, or a non-cancerous change in a milk duct. Hormone changes and some medicines can also cause it. Less often, it is related to an infection or breast cancer.

The pattern provides useful clues. Discharge is more likely to need assessment if it comes out without squeezing, affects one breast, appears bloody or clear, or comes from a single opening in the nipple.

Nipple discharge can affect people of any sex. New discharge in a man should be assessed promptly because it is unusual, although it does not automatically mean cancer.

You may notice wetness inside your bra or clothing, crusting on the nipple, or fluid appearing when you press the breast or nipple. There may be no pain.

The fluid may look:

• Milky, white, yellow, green, brown, clear, or blood-stained
• Thin and watery or thick and sticky
• Similar on both sides or different between breasts

Other symptoms can help identify the cause. These include breast pain, redness, warmth, swelling, a lump, nipple changes, missed periods, headaches, or changes in vision.

Milky discharge unrelated to pregnancy or breastfeeding is called galactorrhea. It often affects both breasts and may come from several nipple openings.

Pregnancy and breastfeeding commonly cause milky or yellowish fluid. Small amounts may appear during pregnancy, and milk can remain for some time after breastfeeding ends.

Nipple stimulation can trigger discharge. This includes repeated checking, sexual stimulation, friction from clothing, or pressure during exercise. Frequent squeezing can keep the discharge going.

Hormone or medication effects may increase prolactin, the hormone that supports milk production. Possible medicines include some antipsychotics like olanzapine or risperidone, antidepressants like sertraline or fluoxetine, nausea treatments, blood pressure medicines, opioids like oxycodone or morphine, and hormonal medicines. An underactive thyroid or a prolactin-producing pituitary gland growth can also cause milky discharge. Pituitary growths are usually non-cancerous.

Duct ectasia happens when milk ducts beneath the nipple widen and collect thick fluid. The discharge may be green, yellow, brown, or sticky. It may also cause tenderness or an inward-turning nipple.

Intraductal papilloma is a small, usually non-cancerous growth inside a milk duct. It can cause clear or blood-stained discharge from one breast, often without pain.

Infection or a breast abscess may cause pus-like discharge along with pain, redness, warmth, swelling, or fever. An abscess is a pocket of infected fluid.

Breast cancer is a less common cause. Concern is higher when discharge is spontaneous, bloody or clear, comes from one breast or one duct, or occurs with a lump, skin dimpling, or a new nipple change. These features still have non-cancerous causes, but they should be checked.

Arrange a medical appointment if the discharge:

• Appears without squeezing
• Is bloody, clear, or watery
• Comes from one breast or one nipple opening
• Keeps returning or does not settle
• Occurs with a lump, skin change, or newly inverted nipple
• Starts in a man or after menopause
• Is milky when you are not pregnant or breastfeeding

Seek same-day medical care if your breast becomes red, hot, swollen, and painful, especially with fever or feeling unwell. These symptoms may indicate mastitis or an abscess that needs treatment.

Seek emergency help if you have severe weakness, fainting, confusion, trouble breathing, or rapidly worsening illness. Nipple discharge by itself is rarely an emergency.

A healthcare professional will ask about the discharge, including its colour, whether it appears by itself, and whether one or both breasts are affected. They may ask about pregnancy, breastfeeding, periods, recent nipple stimulation, medicines, headaches, and vision changes.

They will examine your breasts, nipples, and nearby lymph nodes. Depending on the findings, testing may include:

• A pregnancy test
• Blood tests for prolactin or thyroid function
• Ultrasound or mammography to examine the breast and milk ducts
• A sample or biopsy if imaging finds an area that needs closer study

Testing the discharge alone cannot reliably rule out cancer. Imaging and examination are usually more useful when the pattern is concerning.

Treatment depends on the cause. Physiological discharge, meaning discharge related to normal stimulation or hormone activity, may not need medical treatment.

Try not to squeeze or repeatedly check the nipple. This can stimulate more fluid production. A soft breast pad can protect clothing, and a well-fitting bra may reduce friction.

Do not stop a prescribed medicine on your own. If a medicine may be contributing, the prescriber can discuss whether an alternative or adjustment is appropriate.

An infection may need antibiotics. An abscess may also need drainage. Hormone or thyroid problems can be treated according to their cause. A persistent abnormal duct or papilloma sometimes needs surgical removal.

If you are breastfeeding and develop breast pain, redness, or fever, seek timely advice. Continuing regular milk removal is often part of mastitis care, but support should be tailored to your symptoms.

How long discharge lasts depends on its cause. Discharge from stimulation may settle after you stop checking or squeezing. Pregnancy- and breastfeeding-related fluid can continue until hormone levels and milk production decrease.

Medication-related or hormonal discharge may improve after the underlying issue is addressed. Duct-related discharge may continue or return until the affected duct is treated.

Keep follow-up appointments if symptoms persist, even if initial imaging is reassuring. Report any new lump, blood-stained fluid, skin change, or change in the discharge pattern.

Does nipple discharge always mean breast cancer?

No. Most causes are non-cancerous. However, spontaneous discharge from one breast, especially if bloody or clear, should be assessed.

Is green or yellow discharge an infection?

Not always. Thick green, yellow, or brown discharge can occur with duct ectasia. Infection is more likely when there is increasing pain, redness, warmth, swelling, pus, or fever.

Should I squeeze the nipple to check it?

Avoid repeated squeezing. It can keep discharge going and make it harder to tell whether the fluid would occur on its own.

Can medicines cause milky discharge?

Yes. Several medicines can raise prolactin or affect breast tissue. Bring an up-to-date medication list to your appointment, including supplements, but do not stop treatment without advice.