Galactorrhea (guh-lack-toe-REE-uh) is a milky nipple discharge unrelated to the normal milk production of breast-feeding. Galactorrhea itself isn't a disease, but it could be a sign of an underlying problem. It usually occurs in women, even those who have never had children or after menopause. But galactorrhea can happen in men and even in infants.

Excessive breast stimulation, medication side effects or disorders of the pituitary gland all may contribute to galactorrhea. Often, galactorrhea results from increased levels of prolactin, the hormone that stimulates milk production.

Sometimes, the cause of galactorrhea can't be determined. The condition may resolve on its own.

Signs and symptoms associated with galactorrhea include:

• Persistent or intermittent milky nipple discharge
• Nipple discharge involving multiple milk ducts
• Spontaneously leaked or manually expressed nipple discharge
• One or both breasts affected
• Absent or irregular menstrual periods
• Headaches or vision problems

When to see a doctor

If you have a persistent, spontaneous milky nipple discharge from one or both of your breasts and you're not pregnant or breast-feeding, make an appointment to see your doctor.

If breast stimulation — such as excessive nipple manipulation during sexual activity — triggers nipple discharge from multiple ducts, you have little cause for worry. The discharge probably doesn't signal anything abnormal, and this discharge often resolves on its own. If you have persistent discharge that doesn't go away, make an appointment with your doctor to get it checked out.

Nonmilky nipple discharge — particularly bloody, yellow or clear spontaneous discharge that comes from one duct or is associated with a lump you can feel — requires prompt medical attention, as it may be a sign of an underlying breast cancer.

Galactorrhea often results from having too much prolactin — the hormone responsible for milk production when you have a baby. Prolactin is produced by your pituitary gland, a small bean-shaped gland at the base of your brain that secretes and regulates several hormones.

Possible causes of galactorrhea include:

• Medications, such as certain sedatives, antidepressants, antipsychotics and high blood pressure drugs
• Opioid use
• Herbal supplements, such as fennel, anise or fenugreek seed
• Birth control pills
• A noncancerous pituitary tumor (prolactinoma) or other disorder of the pituitary gland
• Underactive thyroid (hypothyroidism)
• Chronic kidney disease
• Excessive breast stimulation, which may be associated with sexual activity, frequent breast self-exams with nipple manipulation or prolonged clothing friction
• Nerve damage to the chest wall from chest surgery, burns or other chest injuries
• Spinal cord surgery, injury or tumors
• Stress

Idiopathic galactorrhea

Sometimes doctors can't find a cause for galactorrhea. This is called idiopathic galactorrhea, and it may just mean that your breast tissue is particularly sensitive to the milk-producing hormone prolactin in your blood. If you have increased sensitivity to prolactin, even normal prolactin levels can lead to galactorrhea.

Galactorrhea in men

In males, galactorrhea may be associated with testosterone deficiency (male hypogonadism) and usually occurs with breast enlargement or tenderness (gynecomastia). Erectile dysfunction and a lack of sexual desire also are associated with testosterone deficiency.

Galactorrhea in newborns

Galactorrhea sometimes occurs in newborns. High maternal estrogen levels cross the placenta into the baby's blood. This can cause enlargement of the baby's breast tissue, which may be associated with a milky nipple discharge. This milky discharge is temporary and resolves on its own. If the discharge is persistent, the newborn should be evaluated by a doctor.

Finding the underlying cause of galactorrhea can be a complex task because there are so many possibilities.

Testing may involve:

• A physical exam, during which your doctor may try to express some of the fluid from your nipple by gently examining the area around your nipple. Your doctor may also check for breast lumps or other suspicious areas of thickened breast tissue.
• Analysis of fluid discharged from the nipple, to see if fat droplets are present in the fluid, which can help confirm the diagnosis of galactorrhea.
• A blood test, to check the level of prolactin in your system. If your prolactin level is elevated, your doctor will most likely check your thyroid-stimulating hormone (TSH) level, too.
• A pregnancy test, to exclude pregnancy as a possible cause of nipple discharge.
• Mammography, ultrasound or both, to obtain images of your breast tissue if your doctor finds a breast lump or observes other suspicious breast or nipple changes during your physical exam.
• Magnetic resonance imaging (MRI) of the brain, to check for a tumor or other abnormality of your pituitary gland if your blood test reveals an elevated prolactin level.

If your doctor suspects that a medicine you're taking might be the cause of galactorrhea, he or she might instruct you to stop taking the medicine for a short time to assess this possible cause.

When needed, galactorrhea treatment focuses on resolving the underlying cause.

Sometimes doctors can't determine an exact cause of galactorrhea. Your doctor might recommend treatment anyway if you have bothersome or persistent nipple discharge. A medication that blocks the effects of prolactin or lowers your body's prolactin level could help eliminate galactorrhea.

Often, milky discharge associated with idiopathic galactorrhea goes away on its own, particularly if you can avoid breast stimulation or medications that are known to cause nipple discharge.

To lessen breast stimulation:

• Try not to overdo it when touching your nipples during sexual activity
• Avoid squeezing, pinching or otherwise manipulating your nipples
• Wear clothing that minimizes friction between the fabric and your nipples

You're likely to start by seeing your family doctor or gynecologist. However, you may be referred to a breast health specialist instead.

What you can do

To prepare for your appointment:

• Take note of all your symptoms, even if they seem unrelated to the reason for which you scheduled the appointment.
• Review key personal information, including major stresses or recent life changes.
• Make a list of all medications, vitamins and supplements that you take.
• Write down questions to ask, noting which are most important to you to have answered.

For galactorrhea, possible questions to ask your doctor include:

• What's likely causing my symptoms?
• Are there any other possible causes?
• What kind of tests might I need?
• What treatment approach do you recommend for me?
• Is there a generic equivalent for the medicine you're prescribing me?
• Are there any at-home remedies I might try?

What to expect from your doctor

Your doctor may ask you questions, such as:

• What color is your nipple discharge?
• Does nipple discharge occur in one or both breasts?
• Do you have other breast signs or symptoms, such as a lump or area of thickening?
• Do you have breast pain?
• How often do you perform breast self-exams?
• Have you noticed any breast changes?
• Are you pregnant or breast-feeding?
• Do you still have regular menstrual periods?
• Are you having trouble getting pregnant?
• What medications do you take?
• Do you have headaches or vision problems?

What you can do in the meantime

Until your appointment, follow these tips to deal with unwanted nipple discharge:

• Avoid breast stimulation to reduce or stop nipple discharge. For instance, avoid stimulating the nipples during sexual activity. Don't wear clothing that causes a lot of friction on your nipples.
• Use breast pads to absorb nipple discharge and prevent it from seeping through your clothing.