Patient education: Prolactin blood test (The Basics)

What is a prolactin blood test? — 

This is a test to check the level of prolactin in the blood. Prolactin is a hormone made in the "pituitary gland," which is a small organ at the base of the brain. It tells the breasts to make milk after giving birth. It also affects other body functions.

It's normal to have high prolactin levels if you are pregnant or recently gave birth. Stress and certain medicines can also cause the level to rise. At other times, high prolactin levels can be a sign of a problem with the pituitary gland, such as a growth called a "prolactinoma." This type of growth is not cancerous.

Why might I get a prolactin blood test? — 

Your doctor might order this test:

●If you have symptoms that could be related to high prolactin levels, such as:

•In females – Irregular periods, trouble getting pregnant, or milk leaking from the breasts.

•In males – Low sex drive, trouble getting an erection, or trouble getting a partner pregnant.

●If you have other symptoms that suggest a growth in the pituitary gland, like headache or trouble seeing

●To monitor treatment for a problem with your pituitary gland

How do I prepare for a prolactin blood test? — 

You need to get a "blood draw." Your doctor or nurse will tell you where to go for this. They might tell you to avoid eating or drinking for some time before the test.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — 

A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — 

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your prolactin level is high, your doctor or nurse will talk to you about what to do next. They might repeat the test, or do more tests to figure out the cause.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

More on this topic

Patient education: Prolactinoma (The Basics)
Patient education: Pituitary adenoma (The Basics)

Patient education: High prolactin levels and prolactinomas (Beyond the Basics)