Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
How the test is performed
A blood sample is needed. For information on how this is done, see: Venipuncture
How to prepare for the test
No special preparation is necessary.
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
Prolactin is a hormone released by the pituitary gland that stimulates breast development and milk production in women. There is no known normal function for prolactin in men.
Prolactin is usually measured when checking for pituitary tumors and the cause of:
Breast milk production that is not related to childbirth (galactorrhea)
Decreased sex drive (libido) in men and women
Irregular or no menstrual periods (amenorrhea)
The normal values for prolactin are:
Males: 2 - 18 ng/mL
Nonpregnant females: 2 - 29 ng/mL
Pregnant women: 10 - 209 ng/mL
The examples above are common measurements for results for these tests. Normal value ranges may vary slightly among different laboratories. Some lab use different measurements or may test different specimens.Talk to your doctor about the meaning of your specific test results.
Note: ng/mL = nanograms per milliliter
What abnormal results mean
People with the following conditions may have high prolactin levels:
Louis S. Liou, MD, PhD, Chief of Urology, Cambridge Health Alliance, Visiting Assistant Professor of Surgery, Harvard Medical School. Previously reviewed by Nancy J. Rennert, MD, Chief of Endocrinology & Diabetes, Norwalk Hospital, Associate Clinical Professor of Medicine, Yale University School of Medicine, New Haven, CT. Review provided by VeriMed Healthcare Network (12/11/2011).