What is galactorrhea?

Galactorrhea (guh-LACK-toe-REE-uh) is milk discharge from the breast that is unrelated to breastfeeding or that happens at least one year after stopping breastfeeding. It usually happens in both breasts, but it can also happen in only one. Both women and men can have galactorrhea.

What causes it?

Usually it is caused by an elevated prolactin level. Prolactin is a hormone that promotes milk production. It is made by a gland in the brain called the pituitary (pih-TOO-ih-TAIR-ee). Some of the common causes of an elevated prolactin level include:

• Pregnancy

• Irritation of the chest wall or nipple

• Medicines such as antipsychotic drugs, some antidepressants, and some blood pressure medicines

• Underactive thyroid (called hypothyroidism)

• Kidney disease

• Pituitary tumor (the most common pituitary tumor that causes galactorrhea is called a prolactinoma; this type of tumor is benign)

• Other problems in the hypothalamus, which is the part of the brain that controls the pituitary gland

Sometimes the cause of galactorrhea can't be found.

What are the symptoms of an elevated prolactin level?

• Milky white discharge from the nipples (it may also be yellow or greenish). If the discharge is red or bloody, it is probably not galactorrhea. Your doctor may want to test you to find out the cause.

• Headaches (from a pituitary tumor)

• Vision changes (from a pituitary tumor)

• An absence of menstrual periods or periods that are not regular

• Less interest in sex

• Erectile dysfunction

• Osteoporosis (from low levels of sex hormones, like estrogen or androgen, caused by the high prolactin levels)

What tests will I need?

Your doctor might do a blood test to see if you have an elevated prolactin level. If you do, other blood tests are usually done to figure out what is causing your increased prolactin level, such as a pregnancy test and tests of thyroid and kidney function. If no obvious causes are found, your doctor might do an MRI (magnetic resonance imaging) of your head to see if you have a tumor or abnormality around the pituitary gland.

How is it treated?

Treatment usually depends on what is causing the galactorrhea. Sometimes, if the galactorrhea does not bother you, it does not need to be treated. If a certain medicine is causing the galactorrhea, your doctor may prescribe a different one.

Most tumors that cause galactorrhea are not cancerous and can usually be treated with medicine. Surgery is rarely needed.

Where can I find more information?

Your doctor

AAFP's Patient Education Resource

• Web site: https://familydoctor.org/familydoctor/en/diseases-conditions/galactorrhea.html