Prolactin Test (Prolactin). This test measures the level of prolactin hormone in the blood, which is primarily produced by the pituitary gland. This hormone plays a vital role in regulating various biological functions, including stimulating breast milk production after childbirth and affecting the menstrual cycle and female fertility. The test is usually performed when symptoms such as menstrual irregularities, infertility, or abnormal breast discharge are present. Elevated prolactin levels may indicate conditions such as pituitary tumors, polycystic ovary syndrome (PCOS), or other disorders affecting the pituitary gland. Overall, the prolactin test is an important tool for diagnosing and monitoring hormonal disorders, helping doctors determine the most appropriate treatment for patients.