Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Prolactinoma ?
    ### Response:
    A doctor will test for prolactin blood levels in women with unexplained milk secretion, called galactorrhea, or with irregular menses or infertility and in men with impaired sexual function and, in rare cases, milk secretion. If prolactin levels are high, a doctor will test thyroid function and ask first about other conditions and medications known to raise prolactin secretion.
    