Prolactin Hormone Test in Idaho

What this test measures

Prolactin is secreted by the pituitary gland and plays a central role in lactation. Its release is regulated by other signals from the brain, and levels fluctuate during the day and in response to factors such as sleep, stress, exercise, and meals. Because of this natural variability, an isolated value is interpreted carefully and may be repeated when it is above the reference range.

The test is performed on a serum sample, and results are reported as a quantitative concentration using the laboratory's units. When a high result needs clarification, the laboratory may perform additional analysis to check for macroprolactin, a larger form of the hormone that is usually not biologically active. Related tests such as thyroid function or other pituitary hormones may be ordered together.

People may order this test when a healthcare provider is evaluating irregular or absent periods, unexpected milk production, fertility concerns, or symptoms that could relate to pituitary function. It can also be used to follow a known prolactin abnormality over time. A qualified healthcare provider should interpret the result with the person's history, medications, and other laboratory findings.