- Low Levels
- High Levels
- When to See the Doctor
What are prolactin levels?
Prolactin, or milk hormone, is the hormone that causes breasts to grow. It is produced by the pituitary gland located at the bottom of the brains of both men and women. Prolactin is also responsible for the creation of breastmilk after a baby is born and 300 other functions.
When there is too much prolactin in the blood of a man or woman who is not pregnant, it is called hyperprolactinemia. People who have this condition amount to a third of all women in their childbearing years. Although these women have healthy ovaries (the reproductive organs that carry a woman’s eggs/ova) they experience irregular periods.
A person with low prolactin levels is said to have hyperprolactinemia, or prolactin deficiency. Lower levels of prolactin usually do not need medical treatment.
Symptoms of low and high prolactin levels
Women who have low levels of prolactin in the blood may experience the following:
Although some people who have high prolactin levels don’t show any signs and symptoms, both men and women may have difficulty having children and decreased desire for sex.
Other signs and symptoms include:
- Erectile dysfunction—trouble getting or keeping an erection
- Breast enlargement, also called gynecomastia
- Decreased muscle mass and body hair
- Vaginal dryness, leading to pain during intercourse
- Problems with menstruation—having no periods or irregular periods
- Production of breast milk when not pregnant or nursing
Women with high prolactin levels may also experience galactorrhea. A woman who has this condition may find it difficult to get pregnant. Her breasts may also start producing milk while she is not pregnant. Ninety percent of women with galactorrhea also have hyperprolactinemia.
Causes of low levels of prolactin
There may be a number of causes of low levels of prolactin, including the following.
A condition that causes an inability to breastfeed.
There is evidence that the reduction of breast milk in women who smoke cigarettes may be linked to an effect of nicotine on the production of prolactin.
Retained placental fragments
The placenta contains hormones that are known to decrease prolactin levels.
Causes of high levels of prolactin
Prolactinoma (pituitary tumor)
A non-cancerous growth or tumor on the pituitary gland. The tumor can be large or small, and it produces high levels of prolactin. Prolactinomas occur more in women than in men but rarely in children.
Hypothyroidism or underactive thyroid
Some other common causes are:
- Medicines given for depression, psychosis, and high blood pressure
- Herbs, including fenugreek, fennel seeds, and red clover
- Irritation of the chest wall (from surgical scars, shingles, or even a too-tight bra)
- Stress or exercise (usually excessive or extreme)
- Certain foods
- Nipple stimulation
- Birth control pills
When to see your doctor about prolactin
A prolactin test measures the level of prolactin in your blood. The following are indications that you should talk to your doctor about doing a PRL.
If you are a woman:
- Production of breast milk if you are not pregnant or breastfeeding
- Nipple discharge
- Changes in vision
- Irregular periods
- Periods that have stopped completely before the age of 40, known as premature menopause
- Breast tenderness
If you are a man:
Diagnosis and tests for low and high prolactin levels
Apart from the prolactin levels test, your doctor may conduct blood tests to measure levels of prolactin. If you just had a meal or are stressed, your prolactin levels might show up higher. In such a case, your doctor will have you fast and relax, then repeat the test.
Doctors will also ask about other conditions and medication use, and rule out pregnancy. Other advanced tests may include a scan of your brain through magnetic resonance imaging (MRI) to check for a tumor of the pituitary gland.
Treatment for high levels of prolactin
Your doctor will treat you according to the cause of the condition. Usually, your doctor will prescribe thyroid replacement medicine to bring your prolactin levels back to normal. If a medicine is the cause, your doctor will help you find something to get your levels back to normal. If a cause was not found, there is no need to get treated for the condition.
A woman with hyperprolactinemia may continue taking birth control pills to prevent pregnancy or make their periods regular. However, women who cannot create estrogen due to high levels of prolactin should get treated.
Health Solutions From Our Sponsors
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Hormone Health Network: "Hyperprolactinemia."
The National Institute of Diabetes and Digestive and Kidney Diseases: "Hypothyroidism (Underactive Thyroid)."
Penn Medicine: "Prolactinoma."
Medscape: "Prolactin Deficiency."
Medscape: "Prolactin Deficiency Clinical Presentation."
Trends in Endocrinology & Metabolism: "The endocrine effects of nicotine and cigarette smoke."
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You and Your Hormones: "Prolactin."