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Last full review/revision Feb 2021| Content last modified Feb 2021
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What is galactorrhea?

Galactorrhea is when your breasts make milk when you aren’t breastfeeding a baby. Both men and women can get galactorrhea.

  • Galactorrhea is usually caused by a tumor in your pituitary gland

  • Some of the problems that cause galactorrhea also can cause infertility in both men and women

  • Tests include imaging of the pituitary with CT or MRI scans of the brain, and measurement of the pituitary hormone prolactin

  • Doctors treat galactorrhea with medicine and sometimes surgery

The pituitary gland is a pea-sized bit of tissue at the bottom of your brain that makes hormones. Hormones are chemicals that stimulate other cells or tissues into action. 

What causes galactorrhea?

Prolactin is a hormone from your pituitary gland that causes your breasts to make milk. Prolactin normally increases in women who have just given birth, so they can breastfeed their baby. Too much prolactin causes your breasts to make milk even when you're not pregnant. Prolactin can even make a man's breasts produce milk.

The most common cause of galactorrhea in men and women is:

  • A tumor on your pituitary gland that causes the gland to make too much prolactin

Other causes of having too much prolactin include:

  • Certain medicines (some high blood pressure medicines and birth control pills)

  • Underactive thyroid gland (hypothyroidism)

  • Liver disease

  • Certain lung cancers

Having too much prolactin also can affect sexual function and fertility in men and women.

What are the symptoms of galactorrhea?

For women:

  • Your breasts making milk unexpectedly

  • Not having periods, or having fewer periods

  • Vaginal dryness because of low estrogen levels

  • Sometimes, excess body hair (hirsutism)

For men:

In both women and men, a large tumor can press on nerves in the brain and cause headaches or partial blindness.

How can doctors tell if I have galactorrhea?

Doctors know you have galactorrhea because your breasts are making milk for no reason. To know the cause of the galactorrhea, they'll do tests such as:

  • Blood test to measure your prolactin level

  • CT scan or MRI of the brain

How do doctors treat galactorrhea?

Doctors treat galactorrhea with:

  • Medicine to stop your pituitary gland from making prolactin

  • Surgery to remove a tumor, if you have one and if medicine doesn't work

  • Radiation therapy, if both medicine and surgery don't work

If your symptoms are mild and don't bother you, doctors may not treat your galactorrhea. You may need to take estrogen for low estrogen levels, and doctors will do follow-up CT scans or MRI each year to make sure your pituitary tumor isn't growing larger.

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