Prolactin - Serum

Description

A prolactin (PRL) test measures the level of prolactin in a sample of your blood. Prolactin is a hormone produced by the pituitary gland, a small gland at the base of the brain. Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs.

Prolactin affects many body processes. But its main role is to signal breast tissue to grow during pregnancy and make milk for breastfeeding after birth. So, prolactin levels in pregnant women and new mothers are normally high.

In nonpregnant women and men, prolactin levels are normally low.

Having higher-than-normal prolactin levels (hyperprolactinemia) can affect the body in different ways:

• In women, it can affect how the ovaries work and can cause menstrual problems and infertility.
• In men, it can affect how the testicles work and can cause a lower sex drive and erectile dysfunction (ED). Also known as impotence, ED is the inability to get or maintain an erection.
  In men and women who are not pregnant or breastfeeding, it can signal your body to start making breastmilk.

Higher-than-normal prolactin levels can have different causes:

• Prolactinoma, a benign (noncancerous) tumor growing on the pituitary gland. This is the most common cause. This type of tumor makes prolactin, which leads to higher-than-normal levels of prolactin in the blood.
• Certain medicines.
• Certain health conditions, such as hypothyroidism (underactive thyroid), kidney disease, and chest injuries
• Other pituitary gland tumors.

A prolactin test can't show the cause of higher-than-normal prolactin levels. But finding out what your levels are can help your health care provider decide which other tests you need to diagnose the cause of your symptoms.

Other names: PRL test, prolactin blood test.

Source: National Institutes of Health (NIH) U.S. Department of Health and Human Services.