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Prolactin Levels

What is a prolactin levels test?

A prolactin (PRL) test measures the level of prolactin in the blood. Prolactin is a hormone made by the pituitary gland, a small gland at the base of the brain. Prolactin causes the breasts to grow and make milk during pregnancy and after birth. Prolactin levels are normally high for pregnant women and new mothers. Levels are normally low for nonpregnant women and for men.

If prolactin levels are higher than normal, it often means there is a type of tumour of the pituitary gland, known as a prolactinoma. This tumour makes the gland produce too much prolactin. Excess prolactin can cause the production of breast milk in men and in women who are not pregnant or breastfeeding. In women, too much prolactin can also cause menstrual problems and infertility (the inability to get pregnant). In men, it can lead to lower sex drive and erectile dysfunction (ED). Also known as impotence, ED is the inability to get or maintain an erection.

Prolactinomas are usually benign (noncancerous). But left untreated, these tumors can damage surrounding tissues.

Other names: PRL test, prolactin blood test

What is it used for?

A prolactin levels test is most often used to:

  • Diagnose a prolactinoma (a type of tumor of the pituitary gland)
  • Help find the cause of a woman’s menstrual irregularities and/or infertility
  • Help find the cause of a man’s low sex drive and/or erectile dysfunction

Why do I need a prolactin levels test?

You may need this test if you have symptoms of a prolactinoma. Symptoms may include:

  • Production of breast milk if you are not pregnant or breastfeeding
  • Nipple discharge
  • Headaches
  • Changes in vision

Other symptoms are different depending on whether you are a man or a woman. If you are a woman, symptoms also depend on whether you have gone through menopause. Menopause is the time in a woman’s life when her menstrual periods have stopped and she can’t become pregnant anymore. It usually starts when a woman is around 50 years old.

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Symptoms of excess prolactin in women who have not gone through menopause include:

  • Irregular periods
  • Periods that have stopped completely before the age of 40. This is known as premature menopause.
  • Infertility
  • Breast tenderness

Women who have gone through menopause may not have symptoms until the condition worsens. Excess prolactin after menopause often causes hypothyroidism. In this condition, the body does not make enough thyroid hormone. Symptoms of hypothyroidism include:

  • Fatigue
  • Weight gain
  • Muscle pain
  • Constipation
  • Trouble tolerating cold temperatures

Symptoms of excess prolactin in men include:

  • Nipple discharge
  • Breast enlargement
  • Low sex drive
  • Erectile dysfunction
  • Decrease in body hair

What happens during a prolactin levels test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You will need to take your test about three to four hours after waking up. Prolactin levels change throughout the day, but are usually the highest in early morning.

Be sure to tell your health care provider about any medicines you are taking. Certain medicines can raise prolactin levels. These include birth control pills, high blood pressure medicine, and antidepressants.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

If your results show higher than normal prolactin levels, it may mean you have one of the following conditions:

  • Prolactinoma (a type of tumor of the pituitary gland)
  • Hypothyroidism
  • A disease of the hypothalamus. The hypothalamus is an area of the brain that controls the pituitary gland and other body functions.
  • Liver disease
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If your results show high prolactin levels, your health care provider may order an MRI (magnetic resonance imaging) test to get a closer look at your pituitary gland.

High prolactin levels may be treated with medicine or surgery. If you have questions about your results, talk to your health care provider.

References

  1. Empower [Internet]. Jacksonville (FL): American Association of Clinical Endocrinologists; Prolactinemia: Excess Quantities of Lesser-Known Hormone Causes Broad Range of Symptoms; [cited 2019 Jul 14]; [about 3 screens]. Available from: https://www.empoweryourhealth.org/magazine/vol6_issue2/prolactinemia_excess_quantities_of_lesser-known_hormone_causes_broad_range_of_symptoms
  2. Esmaeilzadeh S, Mirabi P, Basirat Z, Zeinalzadeh M, Khafri S. Association between endometriosis and hyperprolactinemia in infertile women. Iran J Reprod Med [Internet]. 2015 Mar [cited 2019 Jul 14];13(3):155–60. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4426155
  3. Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2019. Hypothalamus; [updated 2017 Jul 10; cited 2019 Jul 14]; [about 3 screens]. Available from: https://labtestsonline.org/glossary/hypothalamus
  4. Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2019. Prolactin; [updated 2019 Apr 1; cited 2019 Jul 14]; [about 2 screens]. Available from: https://labtestsonline.org/tests/prolactin
  5. Lima AP, Moura MD, Rosa e Silva AA. Prolactin and cortisol levels in women with endometriosis. Braz J Med Biol Res. [Internet]. 2006 Aug [cited 2019 Jul 14]; 39(8):1121–7. Available from: https://www.ncbi.nlm.nih.gov/pubmed/16906287?dopt=Abstract
  6. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [cited 2019 Jul 14]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
  7. National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Hypothyroidism; 2016 Aug [cited 2019 Jul 14]; [about 3 screens]. Available from: https://www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism
  8. National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Prolactinoma; 2019 Apr [cited 2019 Jul 14]; [about 3 screens]. Available from: https://www.niddk.nih.gov/health-information/endocrine-diseases/prolactinoma
  9. Sanchez LA, Figueroa MP, Ballestero DC. Higher levels of prolactin are associated with endometriosis in infertile women. A controlled prospective study. Fertil Steril [Internet]. 2018 Sep [cited 2019 Jul 14];110 (4):e395–6. Available from: https://www.fertstert.org/article/S0015-0282(18)31698-4/fulltext
  10. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2019. Prolactin blood test: Overview; [updated 2019 Jul 13; cited 2019 Jul 14]; [about 2 screens]. Available from: https://ufhealth.org/prolactin-blood-test
  11. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Erectile Dysfunction (Impotence); [cited 2019 Jul 14]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=85&ContentID=P01482
  12. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Introduction to Menopause; [cited 2019 Jul 14]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P01535
  13. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Prolactin (Blood); [cited 2019 Jul 14]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=prolactin_blood
  14. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Neurosurgery: Pituitary Program: Prolactinoma; [cited 2019 Jul 14]; [about 5 screens]. Available from: https://www.urmc.rochester.edu/neurosurgery/specialties/neuroendocrine/conditions/prolactinoma.aspx
  15. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Endometriosis: Topic Overview; [updated 2018 May 14; cited 2019 Jul 14]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/major/endometriosis/hw102998.html
  16. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Prolactin: Results; [updated 2018 Nov 6; cited 2019 Jul 14]; [about 8 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/prolactin/hw47630.html#hw47658
  17. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Prolactin: Test Overview; [updated 2018 Nov 6; cited 2019 Jul 14]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/prolactin/hw47630.html#hw47633
  18. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Prolactin: What Affects the Test; [updated 2018 Nov 6; cited 2019 Jul 14]; [about 9 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/prolactin/hw47630.html#hw47674
  19. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Prolactin: Why It Is Done; [updated 2018 Nov 6; cited 2019 Jul 14]; [about 3 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/prolactin/hw47630.html#hw47639
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