Prolactin testing is used in clinical contexts to evaluate which conditions, and how can prolactin elevations present?

• A. Evaluate diabetic status; elevations always indicate pathology.
• B. Evaluate galactorrhea, infertility, and pituitary adenomas; elevations can be physiological (pregnancy, stress) or pathological.
• C. Evaluate dehydration; elevations occur only with dehydration.
• D. Evaluate electrolyte disorders; elevations are diagnostic.

Answer: (A)

Prolactin testing is used to investigate causes of hyperprolactinemia that manifest with symptoms such as galactorrhea, infertility, and menstrual irregularities, and to help identify prolactin-secreting pituitary tumors. Elevations in prolactin are not all pathological: they can be physiologic, such as during pregnancy, lactation, or in response to stress, sleep, or exercise. They can also be due to pathology, including prolactin-secreting pituitary adenomas, hypothyroidism, renal or hepatic failure, chest wall stimulation, or medications that reduce dopamine inhibition (like many antipsychotics or antiemetics). Clinically, elevated levels may present with galactorrhea, amenorrhea or oligomenorrhea, infertility, and, in men, reduced libido or infertility; larger tumors can cause headaches or visual field defects. Because minor elevations can occur from nonpathologic factors, prolactin levels are interpreted alongside symptoms, pregnancy status, and sometimes repeat measurements.