High prolactin can cause infertility and sexual problems in both women and men. But not every high result means a disease – taking the test correctly matters a great deal.
What is prolactin?
Prolactin is a hormone released by the front part of the pituitary gland. Because it drives breast development during pregnancy and milk production after childbirth, it is popularly known as the “milk hormone”. Women naturally have slightly higher levels than men, and in both sexes its main job is to regulate the reproductive system.
In a woman who is neither pregnant nor breastfeeding, prolactin above normal stops the follicle from maturing, and ovulation does not occur. A high level of prolactin in the blood is called hyperprolactinaemia.
Why does prolactin rise?
Prolactin is a very sensitive hormone and can sometimes rise without any disease. Sleep, stress, physical strain and workouts, protein-rich meals, touching the breasts, pregnancy and breastfeeding are all normal states of a healthy body. Once breastfeeding ends, prolactin returns to normal.
The main causes of an abnormal rise are:
- a pituitary adenoma – prolactinoma;
- certain medicines: antidepressants and other psychiatric drugs, some stomach and blood pressure medicines, herbal preparations;
- an underactive thyroid (hypothyroidism);
- polycystic ovary syndrome;
- chronic kidney failure and liver cirrhosis;
- injury or radiation of the pituitary, or other diseases affecting it.
What is a prolactinoma?
A prolactinoma is a benign growth of the prolactin-producing cells and the most common type of pituitary adenoma. It is seen more often in women and today is mostly known as a cause of infertility.
Which signs should you watch for?
In women:
- irregular periods or periods stopping;
- milky or whitish discharge from the breast without breastfeeding (galactorrhoea);
- breast pain, tension, tenderness;
- reduced sex drive, vaginal dryness;
- difficulty getting pregnant;
- excess hair growth, weight gain, emotional strain.
In men, high prolactin can show up as reduced sex drive, erection problems, infertility, breast enlargement (gynaecomastia) and bone loss. When the adenoma is large, headaches and vision problems can develop in both sexes.
How do you take the test correctly?
Since prolactin can rise with stress, excitement, physical strain and after meals, the test should be taken by the rules:
- after 8–14 hours of fasting and in a calm state;
- the best time for the blood draw is 9:00–11:00 in the morning – very early in the day the result may be high because of sleep;
- sit quietly for 20–30 minutes before the test;
- smoking and alcohol affect the result.
If prolactin comes back high, macroprolactin should also be checked. Macroprolactin is prolactin bound to immunoglobulins, and it can give a falsely high result without a true elevation. A mild rise found by chance and causing no complaints usually needs no treatment – it is monitored with repeat tests at set intervals.
How is prolactinoma treated?
If the rise is thought to be caused by a pituitary adenoma, a contrast MRI of the pituitary is done. If an adenoma is confirmed, the diagnosis is clear and treatment begins. In most cases prolactinoma can be treated with medication, without surgery.
Treatment uses dopamine agonists that reduce prolactin secretion, such as cabergoline. These medicines both lower the hormone level and help the adenoma shrink.
The choice of drug and its dose must be set by a doctor – taking it on your own can cause serious complications. An untreated prolactinoma can grow, press on the optic nerve and lead to vision loss, a shortage of other pituitary hormones and bone loss. If a woman with a prolactinoma becomes pregnant, medical supervision is especially important during this time.
With correct diagnosis and treatment, the ability to have children can be restored in both sexes.
Dr. Samir Shukurov
This article is for general information only and does not replace a medical examination.