Hyperprolactinemia
Hyperprolactinemia is an elevated serum prolactin level with causes ranging from physiologic states and medications to hypothyroidism, renal failure, and a prolactin-secreting pituitary tumor. Diagnosis requires a confirmed elevated prolactin with exclusion of pregnancy, medication effect, and hypothyroidism before attributing the finding to a pituitary adenoma, and first-line treatment for a symptomatic pituitary cause is a dopamine agonist such as cabergoline.
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What this article covers
- Overview
An elevated serum prolactin from any source: hyperprolactinemia is a laboratory finding with a broad differential spanning normal physiology, medication effect, systemic disease, and pituitary tumors, rather than a single disease.
- Epidemiology
Most common cause is physiologic, related to pregnancy or lactation.
- Risk factors
Pregnancy and lactation, the leading physiologic cause.
- Pathophysiology
Tonic dopaminergic inhibition is the normal state: unlike most anterior pituitary hormones, prolactin secretion is under continuous inhibitory control by hypothalamic dopamine; anything that reduces…
- Clinical features
Amenorrhea or oligomenorrhea is the primary presentation in premenopausal women.
- Differential diagnosis
Pregnancy: the most common physiologic cause; distinguished by a positive human chorionic gonadotropin (hCG) test, which should always be checked before extensive prolactin evaluation.
- Diagnosis
The diagnosis requires a confirmed, reproducibly elevated serum prolactin after excluding pregnancy, with the specific cause established by a structured sequence: medication review, thyroid testing…
- Management
First, treat the identified cause rather than defaulting to a dopamine agonist.
- Complications
Infertility, from gonadotropin suppression and anovulation, which can be a presenting complaint.
- Prognosis
Excellent when the cause is reversible: prolactin and gonadal function typically normalize after treating hypothyroidism or discontinuing a causative medication.
- Prevention
Always exclude pregnancy before extensive evaluation of an elevated prolactin in a woman of reproductive age.
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Related articles
- Prolactinoma
Prolactinoma is a prolactin-secreting pituitary adenoma, the most common functional pituitary tumor, presenting with hypogonadism and galactorrhea from prolactin excess or with headache and visual loss from mass effect in larger tumors. Diagnosis requires an elevated prolactin with a pituitary mass on dedicated MRI after excluding pregnancy, medication effect, and hypothyroidism, and first-line treatment is a dopamine agonist, most often cabergoline, which lowers prolactin and shrinks the tumor without surgery in most patients.
- Primary adrenal insufficiency
Primary adrenal insufficiency (Addison disease) is destruction or dysfunction of the adrenal cortex, most often autoimmune, causing combined cortisol and aldosterone deficiency with hyperpigmentation, hyponatremia, and hyperkalemia. Lifelong glucocorticoid replacement with hydrocortisone plus mineralocorticoid replacement with fludrocortisone is required, with sick-day dose increases to prevent adrenal crisis.
- Hypothyroidism
Hypothyroidism is thyroid hormone deficiency, most commonly caused by autoimmune (Hashimoto) thyroid failure in iodine-sufficient countries, diagnosed by an elevated thyroid-stimulating hormone with a low or normal free thyroxine. First-line treatment is levothyroxine dosed at 1.6 mcg/kg lean body weight orally once daily, titrated using thyroid-stimulating hormone rechecked no sooner than 6 weeks after any dose change.