PRL and hypopituitarism: Diagnostic criteria for hypopituitarism: (1) gonadal axis dysfunction: testosterone (TEST) decreased with abnormal follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) levels in adult male patients, estradiol (E2) decreased with normal or decreased FSH and LH or abnormal PRL in female patients, and decreased FSH and LH in children (41).