Prolactin Test

The Prolactin Test measures the level of prolactin (PRL), a hormone produced by the pituitary gland. Prolactin plays a key role in breast milk production (lactation), reproductive health, and metabolism.

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Why is the Test Done?

A doctor may order a Prolactin Test to:

✅ Evaluate irregular menstrual cycles or infertility (in women)
✅ Assess low testosterone or erectile dysfunction (in men)
✅ Diagnose galactorrhea (unexpected breast milk production)
✅ Check for pituitary disorders (such as prolactinoma, a tumor in the pituitary gland)
✅ Investigate symptoms like headaches, vision problems, or fatigue (linked to pituitary issues)

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Normal Prolactin Levels

📌 Levels may vary slightly depending on the laboratory’s reference range.

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Causes of High Prolactin (Hyperprolactinemia)

Physiological (Normal) Causes

🔹 Pregnancy & Breastfeeding – Naturally elevated during these periods
🔹 Stress & Exercise – Can temporarily increase prolactin
🔹 Sleep – Prolactin levels are highest during sleep

Medical Conditions & Disorders

🔴 Prolactinoma (Pituitary Tumor) – Most common cause of high prolactin
🔴 Hypothyroidism (Low Thyroid Hormone Levels) – Can increase prolactin production
🔴 Chronic Kidney Disease (CKD) – Affects hormone clearance
🔴 Polycystic Ovary Syndrome (PCOS) – May cause mild elevations
🔴 Liver Disease (Cirrhosis) – Can alter hormone metabolism

Medications That Can Increase Prolactin

💊 Antidepressants (SSRIs, TCAs) – Example: Fluoxetine, Sertraline
💊 Antipsychotics – Example: Risperidone, Haloperidol
💊 Blood Pressure Medications – Example: Methyldopa, Verapamil
💊 Opioids & Hormonal Drugs – Example: Estrogen therapy

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Causes of Low Prolactin

🩺 Hypopituitarism – Reduced pituitary function
🩺 Dopamine-Agonist Medications (e.g., Bromocriptine, Cabergoline) – Used to treat high prolactin
🩺 Sheehan’s Syndrome – Pituitary damage after childbirth

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Next Steps Based on Prolactin Levels

🔬 Additional Tests May Be Ordered:

• MRI of the Brain (Pituitary Gland Scan) – If prolactin is very high (>200 ng/mL), prolactinoma is suspected.
• Thyroid Function Tests (TSH, Free T4) – To check for hypothyroidism.
• Testosterone (in men) – To assess hormone imbalance.
• FSH/LH & Estradiol (in women) – To evaluate ovarian function.

💊 Treatment & Management:

• If Prolactin is Mildly Elevated → Check for stress, medications, or thyroid issues.
• If Prolactinoma is Diagnosed → Dopamine agonists (Cabergoline, Bromocriptine) may shrink the tumor.
• If Hypothyroidism is Present → Treating with thyroid hormones can normalize prolactin.