Hyperprolactinaemia — what it looks like and what to do
Noticed unexpected breast milk, missed periods, or low sex drive? Those are common signs of hyperprolactinaemia — higher-than-normal prolactin in the blood. Prolactin is a hormone made by the pituitary gland. It helps with milk production after childbirth. When prolactin is too high at the wrong time, it can change periods, fertility, mood, and sexual function.
What causes high prolactin?
There are a few clear causes to know. The most common is a small pituitary tumor called a prolactinoma. Other causes include certain medicines (especially antipsychotics, metoclopramide, and some antidepressants), low thyroid function (hypothyroidism), chest wall injury or irritation, and kidney disease. Pregnancy normally raises prolactin too, so doctors always check pregnancy first when levels are high.
Medications are a frequent culprit. If you take drugs that block dopamine, prolactin can rise because dopamine normally keeps prolactin in check. That’s why knowing every medicine you take — prescription, over-the-counter, or herbal — matters when you see your doctor.
How doctors diagnose and treat it
Diagnosis starts with a blood test. Prolactin is usually measured fasting and without recent breast stimulation. Mild rises may be repeated before more tests. Very high levels (often over 200 ng/mL) usually point to a prolactinoma, and an MRI of the pituitary is the next step. If thyroid tests show low thyroid function, treating that can bring prolactin back to normal.
Treatment depends on the cause and symptoms. If a medication is causing the problem, a doctor might change the drug or adjust the dose. For prolactinomas, the main treatment is a dopamine agonist — usually cabergoline or bromocriptine. These drugs lower prolactin, shrink the tumor, and often restore normal periods and fertility. Side effects can include nausea, dizziness, and tiredness, so doctors start with a low dose and increase slowly.
Surgery (usually transsphenoidal pituitary surgery) is reserved for people who can’t tolerate medication or when the tumor is pressing on the optic nerves. Radiation is rare but used in stubborn cases. For men, treating hyperprolactinaemia can improve libido and sometimes reverse erectile dysfunction. If you want to try for a baby, doctors often aim to normalize prolactin first.
Practical tips: bring a full medicine list to your appointment, don’t stop prescribed meds suddenly, and ask for repeat prolactin testing if the first result is only mildly raised. If you have headaches, vision changes, or sudden sexual or menstrual changes, see your doctor promptly. With the right tests and treatment, most people get back to normal functioning and fertility.
