What it is
Prolactin is a pituitary hormone best known for stimulating breast milk after childbirth. Outside pregnancy and breastfeeding, high prolactin can disturb the hormones that control periods and fertility in women and testosterone in men.
Common causes include:
- Medicines, such as some antipsychotics, anti-sickness medicines and certain antidepressants
- A prolactinoma, a non-cancerous pituitary tumour that makes prolactin
- An underactive thyroid, or kidney or liver disease
- Stress, exercise or breast stimulation before the blood test, which can raise the result temporarily
- Macroprolactin, a harmless form of prolactin that can make results look high
Common symptoms
In women:
- Irregular or absent periods
- Milky discharge from the breasts when not breastfeeding
- Difficulty getting pregnant
- Vaginal dryness or low sex drive
In men:
- Low sex drive or erectile problems
- Breast enlargement
- Reduced fertility
A large prolactinoma can also cause headaches or loss of side vision.
When to see a specialist
- A blood test shows raised prolactin
- You have milky breast discharge and aren't pregnant or breastfeeding
- Your periods have become irregular or stopped
- You have fertility problems or low sex drive without a clear cause
- You take a medicine that can raise prolactin and have symptoms
Treatment and management
- Repeating the test correctly, and checking for macroprolactin, pregnancy, thyroid problems and medicine causes
- Pituitary MRI when a prolactinoma is suspected
- Medicines (dopamine agonists) that lower prolactin and often shrink prolactinomas
- Reviewing medicines that may be responsible, together with the doctor who prescribed them
- Follow-up blood tests, and planning ahead for pregnancy
How an endocrinologist helps
Many people are told they have high prolactin after a single test. Before starting treatment, Dr. Marium Zaman checks whether the result is real and what is causing it, then plans treatment around your symptoms and family plans.
