What is nipple discharge?

Nipple discharge is when fluid comes out from one or both of your nipples. It is common for women to experience nipple discharge while breastfeeding, but at other times, it could be a symptom of several different breast conditions or hormonal imbalances. If you have any unusual nipple discharge or are experiencing it for the first time, talk with your doctor about your next steps.

For women, nipple discharge is especially common during the reproductive years, and it can happen even when you aren’t pregnant or lactating. In men, any discharge from the nipples isn’t normal and is a sign of a health issue.

Types of nipple discharge

Nipple discharge comes in many types, colors and consistencies. When you visit the doctor for breast discharge, your care team will ask questions about your specific type of discharge. Discharge may range in color from clear to green to brown. It can also vary in consistency and be watery, thick or sticky. Sometimes, discharge only happens when you press or squeeze the nipple, or it may come out on its own.

While your nipple discharge may be harmless, it can sometimes indicate a more serious health issue. Discharge colors and their potential causes may include:

  • Bloody nipple discharge: Bloody discharge may happen if you have a papilloma, a harmless wart-like tumor that can grow in the breast. Rarely, this may indicate breast cancer.
  • Clear nipple discharge: If clear discharge only comes from one breast, it could be a sign of breast cancer, a papilloma or a blocked nipple duct.
  • Green nipple discharge: If you notice green discharge, the most common cause is a breast cyst.
  • Yellow discharge from nipple: Cloudy, yellow or pus-like discharge is a common sign of a breast infection.
  • White discharge from nipple: Milky-white discharge is often caused by hormonal changes, like pregnancy or stopping breastfeeding.
  • Brown nipple discharge: Fibrocystic breast changes or blocked ducts sometimes lead to brown nipple discharge.

Hormonal nipple discharge causes

Changes in your hormone levels can cause many effects on your body, including nipple discharge. Discharge related to hormone changes is sometimes milky-white, but it can also be brown, green or yellow. When hormones are the cause, nipple discharge often affects both breasts.

Some natural hormone changes due to your menstrual cycle or events like pregnancy cause nipple discharge. Most of the time, these normal changes aren’t a cause for concern. Ongoing stress may also affect your hormones and lead to nipple discharge. In other cases, nipple discharge is related to medications or medical conditions that affect your hormone levels.

Menstrual cycle changes

Many people have changes in their breasts that follow their menstrual cycle. Often known as fibrocystic breast disease, these normal changes like lumpiness or tenderness happen in the breasts in the week leading up to your period. These changes could include nipple discharge.

Pregnancy and breastfeeding

Even early in pregnancy, hormone changes in your body may lead to nipple discharge. This discharge could range from thin and light to thick and milky. Toward the end of pregnancy and in the early days of breastfeeding, the body produces colostrum, a thick, yellow, nutrient-filled fluid made in the milk production process.


Galactorrhea is a medical term used anytime your breasts are making milk or milky discharge that isn’t related to breastfeeding, usually due to higher-than-normal levels of the hormone prolactin. Galactorrhea could be caused by a medical condition or as a side effect of medications, herbs or drugs.

Hormone-related medical conditions

When medical conditions affect your body’s levels of normal hormones, it could lead to nipple discharge. An underactive thyroid or pituitary tumor often causes hormone-related nipple discharge.


Medications containing synthetic hormones could lead to nipple discharge, such as birth control pills or hormone replacement therapy treatments. Other types of drugs may have nipple discharge as a side effect, including those for blood pressure, depression and acid reflux or opioids and sedatives.

Non-hormonal causes of nipple discharge


While hormonal changes are a common cause of harmless nipple discharge, breast discharge is sometimes a symptom of an underlying medical condition. Getting checked by your doctor when you have ongoing discharge is a good idea. A visit to the doctor can help you find out what discharge is normal and what discharge may need additional care or testing.

Breast cancer can rarely cause breast discharge, whereas other medical conditions are more common. With diagnosis and treatment, your care provider can work with you to monitor or resolve some of the causes of non-hormonal nipple discharge.

Mammary duct ectasia

Women in perimenopause or menopause may experience mammary duct ectasia. In this condition, the milk ducts become inflamed and blocked. Inflamed milk ducts can cause thick, clear, green or brown discharge and red, tender nipples. In some cases, it might also lead to breast infection.


An infection in the breast is called mastitis. When this happens, nipple discharge usually occurs with other symptoms, like a fever and breast pain. The most common breast infection discharge is yellowish in color. If the infection becomes severe, the discharge may also smell bad.

Intraductal papillomas

Papillomas are non-cancerous growths in the milk ducts of the breast. These growths may irritate or cause duct inflammation, leading to bloody nipple discharge. Papillomas are a common cause of non-hormonal breast discharge.

Breast cancer

Nipple discharge can be an early symptom of breast cancer, including intraductal carcinoma. This is why getting checked is essential, especially if you have discharge only in one breast or have other symptoms like a lump or changes to the look and feel of the nipple.

Paget’s disease of the breast

Paget’s disease is a rare cause of nipple discharge. Symptoms start in the nipple and often include bloody discharge. You may have other signs like nipple flattening, tenderness, flaking, burning or redness.

Male nipple discharge

Any male nipple discharge needs to be checked by a doctor. In men, nipple discharge could be caused by gynecomastia (an overdevelopment or enlargement of the breast tissue), an infection, non-cancerous growth in the breast or a blocked duct. It might also be an early warning sign of male breast cancer or other conditions, such as a tumor on the pituitary gland.

Diagnosing breast discharge

If you’re experiencing nipple discharge, a visit to the doctor can give you the answers you need. To diagnose the cause behind your nipple discharge or other related symptoms, your doctor will likely ask you questions about your medical history and perform an exam.

Then, your care team may recommend other tests to gather more information about your health or closely examine your breast tissue. Some standard tests used to diagnose the cause of nipple discharge include blood tests and imaging tests, like a mammogram. The type of tests you need will depend on your breast discharge and other factors unique to your health. 

  • Mammogram: A diagnostic mammogram uses X-ray imaging to take pictures of the breasts.
  • Ultrasound: A breast ultrasound provides images of the breasts to understand the causes of your nipple discharge. This test sometimes helps identify intraductal papilloma.
  • Biopsy: Based on your breast exam or an imaging test, your doctor may use a breast biopsy to take a sample of the tissue in an area of the breast that needs a closer look.
  • Blood test: Blood tests give your care team more information about your prolactin levels and thyroid function, which could be causing nipple discharge.

Our locations near you

We offer several locations for your care, including centers in North and Central Texas that specialize in diagnosing and treating breast health symptoms like nipple discharge.

Frequently asked questions

  • Is nipple discharge a sign of pregnancy?

    Nipple discharge can be a sign of pregnancy. The discharge may be clear if you're early in your pregnancy. Toward the end of pregnancy, milky nipple discharge is common.

  • Is nipple discharge normal?

    For women who are in their reproductive years, nipple discharge can be expected. But it also may be a sign of a medical condition that needs treatment. Nipple discharge in post-menopausal women needs to be checked and it is always considered abnormal in men.

  • Can nipple discharge be a sign of cancer?

    Rarely, nipple discharge is a symptom of breast cancer. However, if you have ongoing nipple discharge, it’s important to ask your doctor if you need additional tests.

  • When is nipple discharge a concern?

    Nipple discharge is a concern when it’s bloody, only affects one breast or leaks out on its own. You should also speak to your doctor if you are experiencing other symptoms along with nipple discharge, like a lump, pain or changes in the look or feel of your nipples.

  • What does nipple discharge look like?

    Nipple discharge can be several different colors and have a range of consistencies. You may have clear, yellow, green, brown, white or bloody discharge. It can be watery, thin, cloudy, thick, sticky or cheese-like.