High Prolactin in Women: Symptoms, Causes and What Your Test Result Means
By Femly Health Editorial Team · 7 November 2026
High prolactin means your blood has more of the hormone prolactin than it should when you are not pregnant or breastfeeding. It can cause irregular or missed periods, milky discharge from the breasts and trouble getting pregnant. Common causes include an underactive thyroid, some medicines, stress and a small, usually harmless growth in the pituitary gland. Simple blood tests can help a doctor find the cause.
What is prolactin and what does it do?
Prolactin is a hormone made in the pituitary gland. This is a small gland at the base of your brain. Its main job is to start and keep up breast milk after childbirth.
That is why high prolactin is normal in pregnancy and while you breastfeed. If you have recently had a baby, you can read more in our guide on when your periods return after delivery.
When you are not pregnant or nursing, your prolactin should stay low. If it stays high, it can interfere with the hormones that control your cycle. These are the hormones that tell your ovaries to release an egg each month.
What are the symptoms of high prolactin in women?
Some women have no symptoms at all. Others notice changes in their periods or breasts first. The most common signs are:
- Periods that come late, come rarely or stop for three months or more
- Milky or clear discharge from one or both breasts when you are not pregnant or breastfeeding
- Trouble getting pregnant
- Low interest in sex
- Vaginal dryness or discomfort during sex
- Headaches or changes in your vision, which can happen if a pituitary growth is large
Over time, high prolactin can lower your oestrogen level. Low oestrogen can affect bone strength, so it is worth getting checked rather than waiting. The Cleveland Clinic lists low bone mass, infertility, low sex drive and irregular periods among the possible effects.
How common is high prolactin?
It is not common in the general population. The Cleveland Clinic says it affects less than 1% of people, and women are more likely to have it than men.
It is much more common in women who already have period problems. The American Society for Reproductive Medicine says about a third of women in their childbearing years with irregular periods and normal ovaries have high prolactin. This is why doctors often check it when they look into missed periods.
What causes high prolactin?
Many things can push prolactin up. Some are harmless and short-lived. Others need a doctor's attention. The table below shows the main ones.
| Cause | What happens | What a doctor may do |
|---|---|---|
| Prolactinoma | A small, usually non-cancerous growth in the pituitary makes extra prolactin | Order an MRI scan and discuss medicines |
| Underactive thyroid (hypothyroidism) | Low thyroid hormone can lead to more prolactin | Check thyroid tests and manage the thyroid |
| Certain medicines | Some medicines for mood, mental health, nausea or blood pressure can raise prolactin | Review your medicine list and decide on any change |
| Stress, sleep and exercise | Physical or emotional stress can raise prolactin for a short time | Repeat the test under calm conditions |
| Other health conditions | Kidney or liver disease and some chest wall problems can play a part | Look at your overall health |
The Health New Zealand patient page lists tumours, stress, some medicines, liver and kidney disease and an underactive thyroid among the causes. The Endocrine Society also notes that a low thyroid sometimes causes high prolactin.
Is high prolactin linked to PMOS or thyroid problems?
They are separate conditions, but they can look alike. PMOS (PCOD/PCOS) is a hormone and metabolic condition that can also cause irregular periods. An underactive thyroid can too.
Because the signs overlap, a doctor usually checks prolactin and thyroid along with other tests when your periods are irregular. You can read how the first two are connected in our article on PMOS (PCOD/PCOS) and thyroid. For a wider look at causes, see irregular periods and what causes them.
Having one of these does not rule out another. A woman can have PMOS and a thyroid problem, or a raised prolactin as well. This is why one clear picture comes from the full set of tests, not from a single number.
How is high prolactin tested?
The test is a simple blood test. Your result depends a lot on how and when you give the sample, so a little planning helps.
- Go in the morning. A prolactin test is usually done about three hours after you wake up, between 8 and 10 a.m., according to Kaiser Permanente.
- Ask if you need to fast. You may be asked not to eat for a few hours before.
- Stay calm and rest for a while. Emotional stress or hard exercise just before the test can raise your level.
- Tell your doctor about all your medicines and supplements.
- If the result is high, expect a repeat test, a thyroid test and sometimes a pregnancy test.
Can stress, poor sleep or exercise raise prolactin?
Yes, but usually only a little and only for a short time. Prolactin rises during sleep and just after waking. It also goes up during physical and emotional stress, which is why the timing of the test matters.
A mild rise from a stressful morning is different from a level that stays high on repeat tests. If your result is only a bit above the range, your doctor may simply ask you to repeat it. Long-term stress can also change your periods in other ways. Our article on stress, cortisol and your periods explains how.
What does a high prolactin result mean?
A single high number does not tell you the cause. Your doctor will look at your symptoms, your medicines, your thyroid test and the repeat prolactin level.
Sometimes the lab finds a large, inactive form of prolactin called macroprolactin. It raises the total number on the report but does not act like the active hormone. If you have no symptoms and the level is high, your doctor may ask for a test to check for it.
If the level is much higher, or you have headaches or vision changes, your doctor may suggest an MRI of the pituitary gland. A prolactinoma is the most common growth found. It is usually not cancer.
How does high prolactin affect periods and pregnancy?
High prolactin can stop ovulation. Without ovulation, periods become irregular or stop, and pregnancy is harder. This is one of the reasons women with high prolactin often first visit a doctor for fertility.
Doctors have ways to manage high prolactin, and many women go on to have healthy pregnancies with proper medical care. If you are trying to conceive, our guide on how long to try before seeing a doctor can help you decide when to ask for help. Do not wait if your periods have stopped or you have breast discharge.
How do doctors manage high prolactin?
It depends on the cause. The Endocrine Society guideline says people with high prolactin and few or no symptoms may not need treatment. It also says that women with symptoms, or who want to become pregnant, need care that fits the cause.
In general, a doctor may:
- Manage an underactive thyroid if that is the cause
- Review a medicine that may be raising prolactin and decide whether a change is safe
- Prescribe a medicine that lowers prolactin if a prolactinoma or another cause needs it
- Monitor your levels over time with repeat tests
All of this needs a doctor's care and follow-up. Medicines, doses and how long you need them are always your doctor's decision.
What can food and lifestyle do alongside medical care?
No food or supplement lowers prolactin on its own. Be careful of websites or sellers who say otherwise. What food and lifestyle can do is support your overall hormone health while your doctor manages the cause.
- Eat regular, balanced meals. Include dal, vegetables, curd, whole grains and enough protein. Our guide on protein for Indian vegetarian women can help you plan.
- Support your thyroid if it is low. If thyroid is part of the picture, see what to eat with hypothyroidism.
- Protect your sleep. Try to sleep and wake at about the same time each day.
- Make room for calm. A short walk, a few slow breaths or a regular break in your workday can lower daily stress.
- Look after your bones. Ask your doctor whether you need to check your calcium and vitamin D levels if your periods have been missing for a long time.
At Femly Health, clinical dietitians and doctors work together on nutrition and lifestyle guidance for hormonal and menstrual health. If you are working on your cycle and fertility, the Fertility & Hormone Health programme is one place this support is offered. It works alongside, not instead of, the care your own doctor gives you.
Can you talk to a doctor about this online?
If you have missed periods, breast discharge or a high prolactin result and are unsure what to do next, a doctor can look at your full history. A Femly doctor can evaluate your concern and give you guidance on tests and next steps through an online doctor consultation. Bring any recent reports, including your thyroid and prolactin results and a list of all the medicines you take.
When to see a doctor
See a doctor if your periods have stopped for three months or more, or if they have become far less regular than usual. See one if you notice milky discharge from your breasts when you are not pregnant or nursing.
Also see a doctor if you have been trying to conceive without success, or if you have a high prolactin result on a report. Do not wait if you also have a new, lasting headache or changes in your vision.
Do not stop any medicine you take for mood, mental health, blood pressure or any other condition without talking to your doctor first. Your doctor can weigh the risks and decide what is best for you.
Frequently asked questions
What are the symptoms of high prolactin in women?
The most common signs are late, rare or missed periods, milky discharge from the breasts when you are not pregnant or nursing, and trouble getting pregnant. Some women also have low interest in sex or vaginal dryness. Some women have no symptoms at all.
What is a normal prolactin level for a woman?
The normal range differs from lab to lab and depends on the test method, so use the range printed on your own report. Levels are higher in pregnancy and while breastfeeding. Your doctor will read your number along with your symptoms and other tests.
Can high prolactin cause irregular periods?
Yes. High prolactin can interfere with the hormones that trigger ovulation. When ovulation slows or stops, periods can become irregular or go missing for months.
Can high prolactin stop you from getting pregnant?
It can make pregnancy harder, because it may stop you from ovulating. Doctors have ways to manage high prolactin, and many women conceive with proper medical care. If you are trying to conceive, ask a doctor to check your prolactin.
Can stress cause high prolactin?
Yes, physical or emotional stress can raise prolactin for a short time. This is why labs ask you to rest before the test, and why doctors often repeat a mildly high result.
Can thyroid problems cause high prolactin?
Yes. An underactive thyroid can lead to higher prolactin in some women. Doctors usually check thyroid tests when prolactin is high.
Which medicines can raise prolactin?
Some medicines for mood, mental health, nausea and blood pressure can raise prolactin. Do not stop any medicine on your own. Your doctor can decide whether a change is right for you.
Is a prolactinoma cancer?
A prolactinoma is a growth in the pituitary gland, and it is usually not cancer. It can cause high prolactin and, if large, headaches or vision changes. A doctor can advise on scans and next steps.
Do I need to fast for a prolactin test?
You may be asked to fast for a few hours, so check with your lab or doctor. The test is usually done in the morning, about three hours after you wake up. Try to stay calm and avoid hard exercise before it.
Can diet lower prolactin levels?
No food or supplement is proven to lower prolactin by itself. Balanced meals, good sleep and stress care support your overall hormone health. They work alongside medical care and do not replace it.