Prolactin Test Explained: Procedure, Normal Range & Causes

The prolactin test is a simple blood test used to measure the level of prolactin hormone in the body. Prolactin plays a crucial role in reproductive health, particularly in women, but it also affects men. Abnormal prolactin levels can cause fertility issues, menstrual irregularities, sexual dysfunction, and other health concerns. Understanding why the test is done, how it works, and what the results mean can help in early diagnosis and effective treatment.

What Is a Prolactin Test?

A prolactin test measures the amount of prolactin hormone present in the blood. Prolactin is produced by the pituitary gland, a small but important gland located at the base of the brain. Its primary function is to stimulate breast milk production after childbirth. However, prolactin also influences menstrual cycles, ovulation, testosterone levels, and overall reproductive health.

Doctors may recommend a prolactin test when symptoms suggest hormonal imbalance or pituitary gland disorders.

Why Is the Prolactin Test Done?

The prolactin test is commonly advised to investigate hormonal or reproductive problems. It helps doctors diagnose the cause of abnormal symptoms and monitor ongoing treatment.

Common reasons for testing include:

• Irregular or absent menstrual periods
• Difficulty getting pregnant
• Milk discharge from breasts without pregnancy or breastfeeding
• Erectile dysfunction or low libido in men
• Unexplained headaches or vision problems
• Suspected pituitary gland disorders

Who Should Get a Prolactin Test?

A prolactin test can be recommended for:

• Women with menstrual irregularities or infertility
• Men with low testosterone levels or sexual dysfunction
• Individuals experiencing unexplained breast discharge
• Patients suspected of having pituitary tumours
• People on medications known to affect prolactin levels

Prolactin Test Procedure: Step-by-Step

The prolactin test is a simple and safe blood test. Let us see how it is done and what you can can do to be prepared for it:

Before the Test

• The test is usually done in the morning, as prolactin levels are highest during sleep.
• You may be advised to avoid stress, exercise, or sexual activity before the test
• Inform your doctor about any medications you are taking.

During the Test

• A healthcare professional draws a small blood sample from a vein in your arm.
• The procedure takes only a few minutes.

After the Test

• You can resume normal activities immediately.
• Results are usually available within 24–48 hours.

Prolactin Normal Range

The prolactin normal range varies slightly depending on the laboratory and individual factors such as gender and pregnancy status.

Typical reference ranges:

• Women (non-pregnant): 5–25 ng/mL
• Men: 5–15 ng/mL
• Pregnant or breastfeeding women: Higher levels are normal

Your doctor will interpret results based on symptoms and medical history rather than numbers alone.

Common Causes of High Prolactin

Elevated prolactin levels are known as hyperprolactinaemia. High levels can disrupt reproductive hormones and cause noticeable symptoms.

Pituitary Tumours (Prolactinoma)

Prolactinomas are benign (non-cancerous) tumours of the pituitary gland that produce excessive prolactin. They are one of the most common causes of persistently high prolactin levels. Depending on their size, they may also cause headaches, vision problems, or hormonal imbalances. Most prolactinomas respond well to medication and rarely require surgery.

Pregnancy and Breastfeeding

During pregnancy and breastfeeding, prolactin levels rise naturally to prepare the body for milk production. This increase is normal and essential for nurturing the newborn. Elevated prolactin during this period does not indicate disease and usually returns to normal once breastfeeding stops.

Hypothyroidism

Low levels of thyroid hormones can stimulate the pituitary gland to release more prolactin. Hypothyroidism is a common and treatable cause of elevated prolactin levels. Treating the thyroid disorder often leads to normalisation of prolactin without additional therapy.

Medications

Certain medications can interfere with dopamine, a chemical that normally suppresses prolactin release. Antidepressants, antipsychotics, some blood pressure medicines, and hormonal treatments may raise prolactin levels. Doctors often review or adjust medications if drug-induced hyperprolactinaemia is suspected.

Chronic Stress

Physical or emotional stress can temporarily increase prolactin secretion. Factors such as lack of sleep, anxiety, intense exercise, or illness may cause short-term elevation. In such cases, repeat testing after stress reduction often shows normal levels.

Chest Wall Injury or Irritation

Injuries, surgery, burns, or chronic irritation to the chest wall can stimulate nerve pathways that increase prolactin release. Conditions such as shingles or repeated trauma in the chest area may lead to elevated levels. Treating the underlying cause usually resolves the problem.

Here are some symptoms of high prolactin:

• Missed or irregular periods
• Infertility
• Breast milk leakage
• Reduced libido
• Erectile dysfunction in men
• Headaches or vision changes

What Does Low Prolactin Mean?

Low prolactin levels are less common and usually not a cause for concern. However, in some cases, they may indicate pituitary gland dysfunction.

Possible Causes of Low Prolactin

• Pituitary damage or injury
• Certain medications (dopamine agonists)
• Hormonal deficiencies

Low prolactin may affect milk production after childbirth but rarely causes other symptoms.

Conditions Linked to Abnormal Prolactin Levels

Several health conditions are associated with abnormal prolactin levels, including:

• Infertility
• Polycystic ovary syndrome (PCOS)
• Hypothyroidism
• Pituitary adenomas
• Sexual dysfunction
• Osteoporosis (long-term high prolactin)

Early detection through a prolactin test helps prevent complications.

How Are Abnormal Prolactin Levels Treated?

Treatment depends on the underlying cause.

Treatment Options Include:

• Medications: Dopamine agonists to reduce prolactin levels
• Thyroid treatment: If hypothyroidism is the cause
• Surgery: Rarely required for large pituitary tumours
• Lifestyle changes: Stress reduction and medication review

Regular monitoring through repeat prolactin tests ensures effective treatment.

Prolactin Test and Fertility

Prolactin plays a key role in regulating reproductive hormones, and abnormal levels can significantly affect fertility in both women and men. In women, elevated prolactin can disrupt ovulation by interfering with the release of hormones needed for regular menstrual cycles. This may result in irregular periods, missed ovulation, or difficulty conceiving.

In men, high prolactin levels can suppress testosterone production, leading to reduced sperm count, low libido, erectile dysfunction, and fertility problems. These hormonal changes often go unnoticed until fertility issues arise, making the prolactin test an important diagnostic tool.

The good news is that prolactin-related fertility issues are usually treatable. Identifying and correcting the underlying cause—whether through medication, thyroid treatment, or stress management, often restores normal hormone balance. Many individuals and couples successfully conceive once prolactin levels return to the normal range, highlighting the importance of early testing and appropriate medical care.

When Should You See a Doctor?

Consult a doctor if you experience:

• Persistent menstrual changes
• Difficulty conceiving
• Unexplained breast discharge
• Sexual health issues
• Severe headaches or vision problems

Timely testing and diagnosis are key to effective treatment.

Importance of Health Insurance for Hormonal Tests

Hormonal disorders often require repeated blood tests, imaging scans, specialist consultations, and long-term follow-up. Having comprehensive health insurance can ease financial stress and ensure uninterrupted care.

Way Forward

The prolactin test is a vital diagnostic tool for identifying hormonal imbalances that affect reproductive and overall health. Whether investigating infertility, menstrual irregularities, or pituitary disorders, early testing allows timely treatment and better outcomes.

With Niva Bupa health insurance plans, you gain access to quality healthcare with benefits such as cashless hospitalisation and a vast network of 10,400+ hospitals across India. Comprehensive coverage helps manage diagnostic tests, specialist consultations, and treatments efficiently, ensuring peace of mind throughout your healthcare journey.

People Also Ask

1. What is a prolactin test?

A prolactin test is a blood test that measures the level of prolactin hormone in your bloodstream. It helps assess pituitary gland function and diagnose hormonal imbalances affecting fertility and reproductive health.

2. Is fasting required before a prolactin test?

Fasting is usually not required for a prolactin test. However, your doctor may give specific instructions based on your medical history or if other tests are being done simultaneously.

3. Is the prolactin test painful?

The test involves a routine blood sample taken from a vein in the arm. Most people experience only mild discomfort, similar to a small pinch, and the procedure is over quickly.

4. When is the best time to take the prolactin test?

Morning hours are preferred, ideally a few hours after waking up. Prolactin levels naturally fluctuate during the day and are highest during sleep, so morning testing ensures more accurate results.

5. Can stress affect prolactin levels?

Yes, physical or emotional stress can temporarily increase prolactin levels. That is why doctors often advise avoiding stress, heavy exercise, or anxiety before the test.

6. Can men undergo a prolactin test?

Yes, men may need a prolactin test if they have symptoms such as low libido, erectile dysfunction, infertility, or unexplained hormonal changes.

7. What medications affect prolactin levels?

Certain medications, including antidepressants, antipsychotics, blood pressure medicines, and hormonal drugs, can raise prolactin levels. Always inform your doctor about any medicines you are taking.

8. Can high prolactin cause infertility?

Yes, elevated prolactin levels can disrupt ovulation in women and reduce testosterone production in men, leading to fertility issues if left untreated.

9. Is high prolactin dangerous?

High prolactin is usually treatable, but ignoring it may lead to long-term complications such as infertility, bone loss, or pituitary gland problems.

10. Can prolactin levels return to normal?

Yes, with appropriate treatment such as medication or management of underlying conditions, prolactin levels often return to the normal range.

11. Does pregnancy affect prolactin levels?

Yes, prolactin levels naturally rise during pregnancy and breastfeeding to support milk production. This increase is normal and does not require treatment.

12. Is repeat testing required?

Yes, doctors may recommend repeat testing to confirm abnormal results, monitor treatment response, or rule out temporary hormonal fluctuations.