Hyperprolactinaemia: what it is and why it matters

High prolactin — called hyperprolactinaemia — happens when the pituitary gland releases too much of the hormone prolactin. Prolactin’s main job is milk production, but when levels stay high it can mess with your periods, fertility, sex drive, and even bone health. You don’t always feel dramatic symptoms, so knowing what to look for helps you get the right tests sooner.

Common signs and when to worry

Women often notice missed or irregular periods, trouble getting pregnant, or unexpected breast milk (galactorrhea). Men may have low libido, erectile problems, or reduced fertility. Both men and women can get headaches or vision changes if a large pituitary tumor presses on nearby structures. If you get new, severe headaches or any loss of peripheral vision, see a doctor urgently — those can signal a growing pituitary mass.

Many things can raise prolactin. Pregnancy and breastfeeding are the most common natural causes. Other causes include small pituitary tumours called prolactinomas, certain medicines (antipsychotics like risperidone, anti-nausea drugs such as metoclopramide or domperidone, some antidepressants), hypothyroidism, chronic kidney disease, and chest wall irritation. Even stress or recent blood tests done after eating can raise levels a little.

How doctors test and diagnose it

Diagnosis starts with a blood test measuring fasting morning prolactin. Your doctor will usually repeat the test and check a pregnancy test first. They’ll also test thyroid function and kidney tests to rule out other causes. If prolactin is clearly raised, an MRI of the pituitary gland is the next step to look for a prolactinoma or other lesion.

Very high prolactin levels often point to a prolactinoma. Mild to moderate rises may come from drugs, thyroid problems, or other causes. Your doctor will combine your symptoms, medication list, and test results to decide what’s driving the rise.

Treatment depends on the cause and your goals. If a drug causes it, switching or stopping that medicine (only under medical supervision) can bring levels back down. For prolactinomas, dopamine agonists — cabergoline or bromocriptine — are the main treatment. They lower prolactin, shrink many tumors, and restore fertility in many people. Surgery is reserved for tumours that don’t respond to medication or those pressing on the optic nerves. Long-term follow-up with blood tests and occasional MRI is common.

Practical tips: bring a full list of medications to your appointment, tell your doctor if you want to get pregnant, and ask whether switching any current drugs is safe. If you ever notice sudden vision loss or very bad headaches, get urgent care. Hyperprolactinaemia is usually manageable once the cause is found and treated.