A check for prolactin (PRL) tests how much of a hormone you have in your blood called prolactin. The hormone is formed in the pituitary gland just below your brain.
When women are pregnant or have just given birth, their levels of prolactin increase in order to make breast milk. But if you’re not pregnant, and even if you’re a man, you can have high levels of prolactin.
If you report having the following symptoms, your doctor will prescribe a prolactin test:
- for women, irregular or no periods
- Discharge of breast milk if you are not pregnant or nursing
- Your breast’s tenderness
- Symptoms of menopause such as hot flashes and dryness of the vagina
It’s hard to get an erection
The development of breast milk (very rare)
lower sex drive
Tenderness of the breast or enlargement
Abnormal Prolactin Level Causes
Normally, men and women who are not pregnant have only small traces of prolactin in their blood. This may be caused by:
prolactinoma (a benign tumor in your pituitary gland that produces too much prolactin)
diseases that affect the hypothalamus (the part of the brain that controls the pituitary gland)
anorexia (an eating disorder)
drugs used to treat depression, psychosis, and high blood pressure
Chest injury or irritation (such as scars, shingles, or irritation).
The ability of the body to remove prolactin can also be affected by kidney disease, liver failure, and polycystic ovarian syndrome (a hormone imbalance that affects ovaries).
How’s the test done?
No special preparations need to be made for a prolactin test. You will receive a sample of blood from a laboratory or hospital. A laboratory worker inserts a needle into your arm’s vein to remove a small amount of blood.
Most people just feel a bit of a sting. Others may experience moderate pain and subsequently see slight bruising.
After a few days, in the form of a number, you will get the results of your prolactin check.
The normal range in your blood for prolactin is:
- males: 2-18 nanograms per milliliter (ng / mL)
- Nonpregnant females: 2-29 ng / mL
- Pregnant females: 10-209 ng / mL
If your level of prolactin is high
if your value falls outside the normal range, this does not automatically mean that you have an issue. Sometimes when you have a blood test, the rates may be higher if you have eaten or have been under a lot of stress.
Depending on which laboratory your doctor uses, what is considered a normal range may also be different.
If you have very high levels— up to 1,000 times the upper limit of what is considered normal— this may be a warning that you have a prolactinoma. This tumor is not cancer, so medication is generally used to treat it. Your doctor may want you to have an MRI in this case.
You will lie inside a magnetic tube as the radio waves are used by the MRI device to create a detailed image of your brain. It will show if your pituitary gland has a mass and if so, how big it is.
If your levels are below the normal range, this could mean that your pituitary gland does not work at full steam. That’s called hypopituitarism. Higher prolactin levels do not usually require medical treatment.
Some drugs can cause low prolactin levels. We include the following:
- Ergot alkaloid derivatives (for severe headaches)
- Levodopa (for Parkinson’s disease)
- Dopamine (Intropine), which is given to people in shock
It is not necessary to treat all cases of high prolactin levels.
The diagnosis will depend on your treatment. If it turns out to be a small prolactinoma or it is not possible to find a cause, the doctor may not prescribe any medication.
Your doctor can prescribe medicine in some cases to lower levels of prolactin. If you have a prolactinoma, the aim is to use medication to decrease tumor size and decrease prolactin volume.