Hyperprolactinemia
Also known as: High prolactin, Prolactinoma (when caused by a pituitary tumour)
Hyperprolactinemia means having too much prolactin in the blood. Prolactin is the hormone made by the pituitary gland that stimulates breast milk production, and it rises normally during pregnancy and breastfeeding. Outside those situations, high levels interfere with the sex hormones, causing irregular or absent periods and infertility in women, reduced libido and erectile dysfunction in men, and milky nipple discharge in either sex. The most common causes are medications, especially certain antipsychotics and antidepressants, and benign pituitary tumours called prolactinomas, which are among the most common pituitary tumours. Other causes include an underactive thyroid, kidney disease, stress and chest wall irritation. Most cases are very treatable: prolactinomas usually shrink with tablets rather than surgery, and medication-related cases often resolve when the drug is adjusted by your doctor.
At a Glance
- Common symptoms
- Irregular, infrequent or absent menstrual periods, Milky discharge from the nipples when not pregnant or breastfeeding (galactorrhea), Difficulty becoming pregnant
- Main treatments
- Treating the underlying cause, such as correcting hypothyroidism, Reviewing medications with the prescribing doctor; a drug may be switched or dose-adjusted, but never stop psychiatric or other prescribed medication on your own, Dopamine agonist tablets (cabergoline or bromocriptine), which lower prolactin and shrink prolactinomas in the large majority of cases
- Category
- Endocrine · Uncommon in the general population but a frequent finding in women with irregular periods or infertility, and in people taking certain medications
- See a doctor if
- Milky nipple discharge when you are not pregnant or breastfeeding
Symptoms
Causes
- Prolactinoma, a benign tumour of the pituitary gland that secretes prolactin
- Medications including antipsychotics, some antidepressants, anti-nausea drugs such as metoclopramide, and some blood pressure drugs
- Underactive thyroid (hypothyroidism), which stimulates prolactin release
- Other pituitary tumours or conditions that compress the pituitary stalk
- Chronic kidney disease or liver cirrhosis, which reduce prolactin clearance
- Physical stress, nipple stimulation, chest wall injury or shingles, and some herbal products
Risk Factors
- Being female, particularly between 20 and 40
- Taking medications known to raise prolactin
- Untreated hypothyroidism
- Chronic kidney disease
- Inherited syndromes such as multiple endocrine neoplasia type 1 (rare)
Diagnosis
- A blood test for prolactin, ideally repeated under resting conditions since stress and recent breast examination can raise it
- A pregnancy test in women, and thyroid, kidney and liver function tests
- A detailed medication review
- MRI of the pituitary gland if no other cause is found or levels are substantially raised
- Visual field testing if a pituitary tumour is large
Treatment
- Treating the underlying cause, such as correcting hypothyroidism
- Reviewing medications with the prescribing doctor; a drug may be switched or dose-adjusted, but never stop psychiatric or other prescribed medication on your own
- Dopamine agonist tablets (cabergoline or bromocriptine), which lower prolactin and shrink prolactinomas in the large majority of cases
- Monitoring without treatment for small prolactinomas that are not causing symptoms, particularly after menopause
- Hormone replacement (estrogen or testosterone) to protect bones and sexual health when prolactin cannot be lowered or in mild cases
- Surgery to remove a pituitary tumour if medication is not tolerated or ineffective, or the tumour threatens vision
- Supportive: adequate calcium, vitamin D and weight-bearing exercise to protect bone density while hormone levels are low
Prevention
- Most causes cannot be prevented, but early recognition prevents complications such as infertility and bone loss
- Have prolactin checked if you develop unexplained irregular periods, nipple discharge or low libido
- Ask about prolactin monitoring if you take a medication known to raise it and develop symptoms
- Keep thyroid disease well treated
- Avoid excessive nipple stimulation or tight, irritating clothing if you are prone to raised prolactin
When to See a Doctor
- Milky nipple discharge when you are not pregnant or breastfeeding
- Periods that have stopped or become very irregular, or difficulty conceiving
- Loss of libido, erectile dysfunction or unexplained breast enlargement in men
- Persistent headaches with vision changes, especially loss of side vision (needs prompt assessment)
- Sudden severe headache with vision loss or collapse, which can indicate bleeding into a pituitary tumour (seek emergency care)
Frequently Asked Questions
Related Conditions
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