The Prolactin Blood Test
Someone might undergo a prolactin blood test for several different reasons. High prolactin levels can occur in kidney disease, polycystic ovary syndrome, and diseases of the hypothalamus region of the brain. In addition a test might be ordered for many other reasons.
- To confirm a pregnancy
- To determine the cause of lactation issues. For example, some people experience a condition called galactorrhea, where lactation occurs in the absence of pregnancy.
- Certain types of sexual dysfunction in men are linked to an increase in prolactin levels.
- Hypothyroidism (low-functioning thyroid gland) can lead to increased levels of prolactin.
- In some women, infertility can be caused by increased prolactin levels, as high levels of this hormone can prevent ovulation and menstrual periods.
- Excess amounts of dopamine can cause prolactin levels to rise.
- Diagnosis of prolactinoma, a benign pituitary gland tumor that can cause increased prolactin production.
- Certain prescription medications, including certain types of anti-psychotics and hypertension drugs, can cause a rise in prolactin.
Like most blood tests, the prolactin blood test is a simple procedure. To perform this test the healthcare worker cleans the inside of the elbow with an antiseptic. This is the most common site for blood to be drawn; alternatively blood might be drawn from a site on the back of the hand.
The healthcare worker then wraps an elastic band around the upper arm to fill the inner elbow vein with blood and make needle insertion easier. Once the needle has been inserted, the elastic band is removed to allow blood to be drawn. In most cases only a mild stinging sensation is felt; in rare cases the injection might cause moderate pain.
This blood test is often ordered with other tests such as those for follicle-stimulating hormone, luteinizing hormone, testosterone, estrogen, and progesterone. These tests are part of the diagnostic process for infertility causes in both men and women.
If thyroid disease is suspected, the prolactin blood test might be ordered in conjunction with blood tests to check thyroid function.