Galactorrhea is the spontaneous flow of milk from the nipple at any time other than the expected nursing period right after a pregnancy.

What Is Galactorrhea?

The word galactorrhea comes from the Greek galaktos, meaning “milk,” and rhein meaning “to flow.” The sugar contained in breast milk is called galactose. Galactorrhea is also sometimes called witch milk, because it occurs at unexpected and unexplained times. Galactorrhea may occur in either females or males. Both females and males have mammary glands in their breasts. The mammary glands in a male are less developed than in a female, but under certain conditions may be stimulated to create milk. Galactorrhea may be intermittent or consistent, scant or abundant, and come from one or both breasts. Milk production is caused by the hormone prolactin, which is made by the pituitary * gland.

What Causes Galactorrhea?

There are many different causes of galactorrhea. In both males and females, the most common cause of galactorrhea is a prolactin-secreting tumor called a prolactinoma that grows in the pituitary gland. Overproduction of prolactin and the development of galactorrhea may also be caused by specific drugs, including some drugs given for high blood pressure (especially methyldopa), some narcotic pain killers, and birth control pills. Birth control pills may cause galactorrhea while a person is taking them and after a person stops taking them because resulting changes in estrogen levels have an effect on prolactin production. Some types of antipsychotic drugs * can cause galactorrhea because they act on a receptor for the neurotransmitter * dopamine * . Prolactin production is also regulated by dopamine. Dopamine inhibits (holds back) prolactin production at inappropriate times. Drugs that inhibit dopamine effectively remove inhibition of prolactin production, with galactorrhea as a result. Other causes of galactorrhea that do not involve high levels of prolactin include an underactive thyroid gland in a condition known as hypothyroidism * , chronic kidney failure, and some spinal cord injuries.

Galactorrhea in newborns

What Role Does the Pituitary Gland Play in Galactorrhea?

The pituitary gland is a pea-sized gland that sits at the base of the brain. It is part of the endocrine system * , which is the system responsible for hormonal regulation of bodily processes such as milk production. The pituitary gland secretes many different hormones that act on other parts of the endocrine system. One of the hormones produced by the pituitary gland is prolactin. The target of prolactin is the mammary glands of the breast.

How Do Prolactinomas Cause Galactorrhea?

Prolactinomas are very small tumors in the pituitary gland that affect the hormone prolactin, and these tumors can cause galactorrhea. The tumors tend to be larger in men than in women when discovered, probably because they come to medical attention later. Individuals with prolactinomas are usually between 20 and 35 years of age.

How Is Galactorrhea Treated?

Treatment of galactorrhea is basically directed at the underlying cause of the problem. Self-manipulation of the breast to check for galactorrhea should be stopped, because it can prolong the condition of galactorrhea. Galactorrhea in infants does not require treatment and will stop on its own. Whether the prolactin level is elevated determines how galactorrhea is treated. Patients with isolated galactorrhea and normal prolactin levels do not require treatment if they are not bothered by the galactorrhea, do not wish to conceive, and do not have another physical abnormality or reduced bone density. Prolactin levels are still measured periodically in these patients.

In patients with elevated prolactin levels, an MRI * may be performed if a pituitary tumor is suspected. Treatment tries to reduce excess prolactin secretion and the symptoms it causes, reducing the size of the prolactinomas and preventing their recurrence. Medications that act on dopamine receptors inhibit further prolactin production, stop galactorrhea, and decrease the size of the prolactinomas. As of 2015, bromocriptine and cabergoline were the dopamine receptor stimulators approved by the U.S. Food and Drug Administration for the treatment of elevated blood prolactin and galactorrhea. However, approximately 12 percent of patients cannot take bromocriptine. The side effects include nausea, vomiting, dizziness, headache, nasal congestion, fatigue, abdominal pain, leg cramps, anxiety, depression, confusion, and constipation. While cabergoline may be easier to take, it has serious side effects, too, and is expensive.

See also Thyroid Disease


Books and Articles

Dawson, Rachel S. “Sudden Onset Galactorrhea in a Teenaged Girl.” Contemporary Pediatrics, May 1, 2015. (accessed October 21, 2015).

Huang, Wenyu, and Mark E. Molitch. “Evaluation and Treatment of Galactorrhea.” American Family Physician 85 (2012): 1073–80. (accessed October 21, 2015).

Websites . “Galactorrhea.” The Global Library of Women's Medicine. (accessed October 21, 2015).

Health System University of Michigan. “Galactorrhea.” University of Michigan Hospitals and Health Centers. (accessed October 21, 2015).


Pituitary Disorders Education and Support. PO Box 571, Brighton, MI 48116. Telephone: 810-923-3379. Website: (accessed October 21, 2015).

* pituitary (pih-TOO-ih-tare-e) is a small oval-shaped gland at the base of the skull that produces several hormones—substances that affect various body functions, including growth.

* antipsychotic drugs are medications that counteract or reduce the symptoms of a severe mental disorder such as schizophrenia.

* neurotransmitter (NUR-otransmiter) is a chemical produced in and released by a nerve cell that helps transmit a nerve impulse or message to another cell.

* dopamine (DOE-puh-meen) is a neurotransmitter in the brain that is involved in the brain structures that control motor activity (movement).

* hypothyroidism (hi-po-THY-roydihzum) is an impairment of the functioning of the thyroid gland that causes too little thyroid hormone to be produced by the body. Symptoms of hypothyroidism can include tiredness, paleness, dry skin, and in children, delayed growth and mental and sexual development.

* endocrine system is a system of ductless glands, including the thyroid and pituitary among others, that secrete hormones and control many bodily functions.

* MRI, short for magnetic resonance imaging, produces computerized images of internal body tissues based on the magnetic properties of atoms within the body.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)