Clear liquid coming out of breast when squeezed female

Maybe you spotted the leakage after having sex. Or perhaps you noticed a dried residue inside your bra when you were getting changed. Either way, fluid seeping out of one or both nipples can be an alarming sight. Assuming you're currently not pregnant or breastfeeding (two times when nipple secretions are totally expected), what you’ve got going on is something called nipple discharge—and it can mean nothing at all or point to some potentially serious health concerns (we’ll get to those).

First, some facts: The nipple has 15 to 20 milk ducts, and fluid can leak out of any of them. "The discharge can be various colors: clear, greenish, white-ish or cloudy, and it can even be bloody," says Anastasia Bakoulis, D.O., a breast and oncologic surgeon at Stony Brook Cancer Center in Stony Brook, NY. We spoke to top breast health experts get clear about nipple discharge.

Is Nipple Discharge Normal?

It can be. “In premenopausal patients, it’s a very common finding, particularly on manipulation [meaning after squeezing your nipple],” says Dr. Bakoulis. According to research, 50% to 80% of women in their reproductive years have nipple discharge, and only 6.8% of these are referred to a breast surgeon. In a premenopausal woman, nipple discharge is usually related to hormones—and in most cases, it’s normal. “The breast is like a super-modified sweat gland,” says Dr. Bakoulis. “If you manipulate the breast or nipple, you will almost always elicit some sort of discharge.” (Who knew?) Nipple discharge can occur from intimacy, wearing a tight bra, or even going from a hot to a cold environment (such as stepping out of the shower). “The muscles in the nipple contract and can cause discharge to seep out,” says Dr. Bakoulis.

When is nipple discharge not normal? It’s less common in a post-menopausal woman. “Nipple discharge in a post-menopausal female is more concerning,” Dr. Bakoulis says. It’s also more worrisome when accompanied by additional symptoms such as headaches or neurological symptoms, breast lumps, or fever (more on these later).

And while it can occur in men, it’s not considered normal for guys and should always be evaluated by a doctor.

Types of Nipple Discharge

Nipple discharge comes in a whole range of colors, but hear this: Our experts don't want you to put too much thought into the color of your nipple discharge. Almost all the various shades can be within the realm of normal. “The color isn't usually the concerning part,” says Dr. Bakoulis.

Of course, bloody red is the most nerve-wracking color of all, but in most cases, the cause of the bloody discharge is benign (non-cancerous), she says. Still, the color can indicate various conditions and reasons. Here’s a general guide:

White or Cloudy Discharge

Is your discharge white? Naturally, breast milk is a possibility if you are breastfeeding. But a white-ish color may also be a sign of something called galactorrhea, which is caused by increased levels of the hormone prolactin in your body. In addition to breastfeeding, prolactin levels may rise due to certain medications, supplements, or as a symptom of hypothyroidism.

Yellow Discharge

This can be due to normal hormonal fluctuations, fibrocystic changes in the breast, or possibly an infection. “Yellow secretions (like pus) can be a sign of infection,” says Deepali Kashyap, MD, a functional gynecologist in Henderson, NV. If so, it will likely be accompanied by breast tenderness, fever, and redness.

Green Discharge

Green sticky discharge can signal a condition called mammary duct ectasia. That’s a fancy way of saying you have inflammation in the walls of your milk duct. Mammary duct ectasia typically resolves on its own but sometimes requires an antibiotic. Talk with your doctor to see if you need one.

Brown Discharge

This is sometimes associated with fibrocystic breasts (a.k.a. lumpy breasts). Brown discharge can also be dried blood and a sign of intraductal papilloma, a non-cancerous growth that grows inside the milk ducts.

Clear Discharge

A clear fluid is usually hormonal and not concerning. If it's a slightly opaque color, the discharge can signify prolactinoma, a non-cancerous tumor in the pituitary gland.

Bloody Discharge

As mentioned, blood is the most alarming shade of nipple discharge. It can stem from trauma to the breast and a benign condition such as intraductal papilloma or breast cancer in rare cases.

Black Discharge

Black discharge, though not common, can also be a sign of mammary duct ectasia. This is when there is inflammation in the walls of your mammary ducts.

Symptoms Along With Nipple Discharge

As mentioned, nipple discharge is often normal and nothing to worry about, except when it comes with other symptoms. For example, call your doctor if you’re experiencing milky discharge, headaches, pain behind the eyes, blurry vision, or other neurological symptoms. “Certain brain tumors can cause this, including prolactinoma, a benign tumor on the pituitary gland,” says Dr. Kashyap. If these are your symptoms, your doctor will likely request an MRI of the brain.

In other cases, symptoms such as fever, tenderness, inflammation, redness—in combination with nipple discharge—may indicate that you have an infection. Other worrisome symptoms include lumps in your breasts or under your armpits, breast skin texture changes, and discoloration. Along with nipple discharge, these are all potential signs of breast cancer. See your doctor to make sure it’s nothing serious.

Causes of Nipple Discharge

Experts break nipple discharge causes into two groups: physiologic discharge, which occurs from something systemic such as hormonal changes, and pathologic discharge, which occurs from something within the breast (such as infection).

Physiologic discharge is often spontaneous (not from manipulation) and on one side. Examples of physiologic nipple discharge include pregnancy, breastfeeding, postpartum discharge (which can last as long as two years), miscarriage or abortion, hormonal fluctuations during the menstrual cycle, fibrocystic changes in the breast.

Pathologic causes include infection, abscess, pituitary tumor, breast trauma, endocrine disease such as hypothyroidism, duct ectasia (inflammation in the duct), and intraductal papilloma (a non-cancerous growth), medications that affect dopamine levels such as oral contraceptives and antidepressants, and certain types of breast cancer (read on for more on that).

Nipple Discharge in Men

It is a rare occurrence, but men can experience nipple discharge. Possible causes include breast cancer, infection, duct ectasia, or a tumor. Unlike in women, nipple discharge in men is almost always the sign of a health issue that warrants your doctor’s advice.

Nipple Discharge and Cancer

While nipple discharge can occur with breast cancer, it’s not very common. Research has shown that nipple discharge is a sign of breast cancer in only 3% to 9% of patients. When it does occur, it's typically from ductal carcinoma in situ, an early-stage form of cancer that starts in the milk ducts. It can also happen with Paget's Disease, a rare disease associated with breast cancer that affects the nipple.

When to See a Doctor

Any discharge is worth mentioning to your doctor or a breast specialist. “Pre- or post-menopausal, individuals with nipple discharge deserve some type of workup,” says Dr. Bakoulis. Your doctor may do blood work to check prolactin levels (elevated with pituitary tumors), hormone levels, and thyroid function. “If someone has yellow discharge, we may culture it,” adds Dr. Kashyap. A younger patient may get an ultrasound of the breast. “And a patient who is 40 years and older should have a mammogram,” she says. Often, an MRI will be done to check for intraductal papilloma. Regardless of whether your nipple discharge turns out to be serious or not (most likely not), you’re better off seeing your doctor and knowing for sure, than worrying and wondering.

You should know: The answer above provides general health information that is not intended to replace medical advice or treatment recommendations from a qualified healthcare professional.

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Krista Bennett DeMaio

Krista Bennett DeMaio has well over a decade of editorial experience. The former magazine-editor-turned-freelance writer regularly covers skincare, health, beauty, and lifestyle topics. Her work has appeared in national