Prolactin
Test Overview
The Prolactin test measures the level of prolactin, a hormone produced by the pituitary gland. Prolactin plays a key role in lactation (milk production) and also influences the reproductive system. Prolactin levels can be measured in the blood to assess conditions related to reproductive health, fertility, and pituitary disorders. Elevated or low prolactin levels can indicate problems with the pituitary gland, hypothyroidism, pregnancy, or other underlying health conditions.
The Prolactin test is a useful diagnostic tool for evaluating hormonal imbalances and potential pituitary disorders. Abnormal results should be investigated further with the help of a healthcare provider to identify the underlying cause and determine appropriate treatment options.
Test Uses
- Evaluate fertility: High prolactin levels can interfere with the menstrual cycle and ovulation, leading to infertility.
- Investigate unexplained lactation: Prolactin levels are often checked in women who are not breastfeeding but experience galactorrhea (milk production).
- Monitor pituitary function: Abnormal prolactin levels can indicate problems with the pituitary gland, such as pituitary tumors.
- Assess sexual dysfunction: High prolactin levels can also be linked to low libido, erectile dysfunction, or gynecomastia in men.
Prolactin Test Results & Ranges
| Test Component: | Normal Range: | Abnormal (Possible Conditions): |
|---|---|---|
| Prolactin Level | Female (non-pregnant): 4.8–23.3 ng/mL Male: 4.0–15.2 ng/mL | High Prolactin (Hyperprolactinemia): Can indicate pituitary tumor (prolactinoma), hypothyroidism, chronic stress, medications (e.g., antipsychotics), or kidney disease. Low Prolactin: Can be seen in pituitary insufficiency, hypothalamic disease, or following radiation therapy to the pituitary gland. |
Expected Turnaround Time
- Results Available: Typically within 1–2 business days.
Specimen Requirements
- Sample Type: Blood sample (venipuncture).
- Container: Serum separator tube (SST).
Collection Instructions:
- Timing: Prolactin levels fluctuate throughout the day, often higher in the morning. It is recommended to take the sample in the morning and after rest (to avoid stress-related elevations).
- Fasting: Fasting is generally not required for this test, but patients should avoid heavy physical activity or stress before the test.
- Medications: Inform your healthcare provider of any medications being taken, especially those that can increase prolactin levels, such as antipsychotics, antidepressants, or blood pressure medications.
Test Details
Clinical Use: The Prolactin test helps evaluate pituitary gland function, fertility, and lactation issues. Abnormal prolactin levels can be linked to a variety of conditions, including prolactinomas (pituitary tumors), hypothyroidism, and stress. Monitoring prolactin levels is especially important in the context of fertility concerns, unexplained lactation, or when investigating possible pituitary disorders.
Limitations: Prolactin levels can be temporarily elevated due to stress, exercise, or sleeping, so multiple tests might be necessary for an accurate diagnosis. High prolactin levels do not always indicate a prolactinoma; other factors like pregnancy, medications, and hypothyroidism can contribute to elevated prolactin. A comprehensive assessment is required to determine the underlying cause of abnormal prolactin levels, and additional tests such as MRI or thyroid function tests may be recommended.