Hyperprolactinemia
A higher-than-normal level of prolactin, the hormone that drives breast milk production. It can cause milky discharge, loss of periods, low libido and infertility. Causes range from harmless (pregnancy, medications) to a pituitary tumour, so a raised prolactin is worth investigating.
What it is
Prolactin is a pituitary hormone whose main job is to stimulate breast milk production, and it is naturally high in pregnancy and breastfeeding. Hyperprolactinemia means the level is raised outside those normal states, and it matters because too much prolactin suppresses the sex hormones — interrupting periods, lowering testosterone, reducing fertility and libido — and can cause milky nipple discharge in either sex. The causes span a wide range. Very common ones are medications (particularly some for nausea, and many antipsychotics), an underactive thyroid (which drives prolactin up), stress, and nipple stimulation. Importantly, a prolactin-secreting pituitary tumour (prolactinoma) is a key cause to identify, especially when the level is high. A large non-secreting pituitary tumour can also nudge prolactin up modestly by pressing on the gland's stalk. Diagnosis involves confirming the raised level, excluding pregnancy and medication effects, checking thyroid function, and — if these don't explain it — an MRI of the pituitary. Treatment targets the cause: stopping or changing a drug, treating the thyroid, or medication (and occasionally surgery) for a prolactinoma.
Key lab markers
- Prolactin — the defining test; a markedly high level suggests a prolactinoma, a modest rise is often from medication or other causes.
- TSH and free T4 — an underactive thyroid raises prolactin and is easily treated.
- Estradiol / testosterone, LH, FSH — assess the knock-on suppression of sex hormones.
- Pregnancy test — pregnancy is a normal cause and must be excluded.
- MRI of the pituitary — if a tumour is suspected (not a blood marker).
Symptoms
- Milky nipple discharge (galactorrhoea), in women or men
- Irregular, absent or missed periods
- Low libido and, in men, erectile dysfunction
- Difficulty conceiving (reduced fertility)
- In a large pituitary tumour: headaches or visual changes
- Sometimes no symptoms, with the raised level found on testing
Related lab panels
When to discuss with a doctor
A raised prolactin is worth investigating, but it is important not to jump to conclusions — the commonest causes are entirely benign, especially pregnancy and medications, and a mildly raised level often has a simple explanation. The work-up, led by your doctor and often an endocrinologist, confirms the result, reviews medications, checks thyroid function and excludes pregnancy, and arranges a pituitary MRI if a tumour is suspected — which is more likely when the level is high or there are symptoms like visual changes. The condition matters because it is treatable and, untreated, can affect fertility and bone health. Mediora.AI can surface a high prolactin alongside thyroid function and the sex hormones so the pattern is read in context, prompting the right next steps; the interpretation and any treatment belong with your doctor.