Why does hyperprolactinaemia cause a missed period?

High prolactin can reduce the brain signals that tell the ovaries to mature an egg and produce their usual hormones. Without regular ovulation, the uterine lining may not follow its usual pattern, so a period can be delayed or absent. Some people also notice breast milk-like discharge, reduced sexual desire, or difficulty becoming pregnant.

Pregnancy and breastfeeding naturally raise prolactin, but medicines, thyroid disorders, and pituitary problems can also contribute. A missed period has many possible explanations, so the symptom needs context and, when appropriate, testing.

If pregnancy is possible, discuss testing with a healthcare professional. Record the date of the last period, any cycle changes, nipple discharge, headaches, vision symptoms, and all medicines. Your clinician may assess prolactin, thyroid function, pregnancy status, and other hormones before choosing follow-up.

Arrange medical review for repeated missed periods or a missed period with nipple discharge, headaches, or vision changes. Seek urgent help for severe headache, sudden vision loss, fainting, severe pelvic pain, or heavy bleeding.

Ask what could be affecting prolactin, whether medicines should be changed, which tests are needed, how the result relates to fertility, and when a specialist assessment would be appropriate.