Does hyperprolactinaemia cause irregular periods?

Prolactin is a hormone made by the pituitary gland. When levels remain high, the signals that coordinate the ovaries, ovulation and the menstrual cycle may become less regular. Bleeding can arrive earlier or later than expected, and some cycles may not release an egg. Hyperprolactinaemia can also occur with breast milk-like discharge, but symptoms vary.

Irregular periods have many possible explanations, including pregnancy, changes in thyroid function, polycystic ovary syndrome, stress, weight change and some medicines. A symptom alone cannot identify the cause.

Record bleeding dates, cycle changes, medicines and any nipple discharge or headaches. Arrange a medical assessment if the pattern persists or is new for you. A clinician may confirm pregnancy status, review medicines and request a prolactin blood test, often with other hormone tests. The result may need repeating under suitable conditions because stress, recent breast stimulation and poor sleep can affect prolactin.

Treatment depends on the cause. Do not stop a prescribed medicine without advice; your clinician can discuss alternatives or treatment for an underlying pituitary or thyroid problem.

Seek prompt medical advice for persistent cycle disruption, unexpected milk-like discharge, new vision changes or headaches that are worsening. Get urgent help for a sudden severe headache, sudden loss of vision, fainting or heavy bleeding with dizziness. If pregnancy is possible, take a pregnancy test and seek advice about any bleeding or pain.

Could my medicines or another hormone condition be affecting prolactin? Do I need a repeat prolactin test or other hormone checks? What symptoms should make me contact you sooner?