Prolactin Level Test-Why am I having this test?

Prolactin level test is often used to diagnose and monitor problems with the pituitary gland, such as pituitary tumors.

It may also be used to help find the cause of certain other conditions, such as an abnormal absence of menstrual cycles (amenorrhea) or a thyroid gland that does not produce enough hormones (hypothyroidism).

Your health care provider may order this test if you have:

• Irregular menstrual periods.
• Loss of libido.
• Milky fluid coming from your nipples (when not breastfeeding).
• Fatigue.

What is being tested?

This test measures the amount of prolactin in your blood. Prolactin is a hormone that is produced by the pituitary gland. Prolactin levels normally go up and down (fluctuate) due to stress, illness, trauma, or surgery. Increased levels can also be caused by tumors or other health problems.

What kind of sample is taken?

A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.

Tell a health care provider about:

• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.

How are the results reported?

Your test results will be reported as values that indicate the amount of prolactin in your blood. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges are:

• Adult male: 3–13 ng/mL.
• Adult female: 3–27 ng/mL.
• Pregnant female: 20–400 ng/mL.

What do the results mean?

Increased levels of prolactin may mean that you have:

• A pituitary gland tumor.
• Amenorrhea.
• Hypothyroidism.
• Certain pituitary or reproductive syndromes.
• Kidney failure.

Decreased levels of prolactin may indicate:

• Lack of blood to the pituitary gland.
• Pituitary gland failure.

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

Ask your health care provider, or the department that is doing the test:

• When will my results be ready?
• How will I get my results?
• What are my treatment options?
• What other tests do I need?
• What are my next steps?

Summary

• The prolactin level test is often used to diagnose and monitor problems with the pituitary gland, such as pituitary tumors. It may also be used to help find the cause of certain other conditions, such as amenorrhea or hypothyroidism.
• This test measures the amount of prolactin in your blood. Prolactin is a hormone that is produced by the pituitary gland.
• Prolactin levels normally go up and down (fluctuate) due to stress, illness, trauma, or surgery. Increased levels can also be caused by tumors or other health problems.
• Talk with your health care provider about what your results mean.