Symptoms of High Prolactin Levels

High prolactin levels outside of pregnancy and breastfeeding can signal an endocrine disorder or other health concern. High prolactin symptoms include breast enlargement, irregular periods, irritability, and a low sex drive.

Prolactin is a hormone produced by the pituitary gland that stimulates lactation (the production of breast milk). It is also involved in the development of mammary glands, the regulation of the menstrual cycle in females, and the production of sperm in males.

While it is normal for prolactin levels to increase during pregnancy and breastfeeding, abnormal increases—referred to as hyperprolactinemia—can cause sexual dysfunction, infertility, and lactation in non-nursing adults.

This article discusses high prolactin levels. It explains high prolactin symptoms and causes in females and males. It also goes over the diagnostic process for hyperprolactinemia and treatment options.

High Prolactin Symptoms in Females

Females are more commonly affected by hyperprolactinemia than males. Studies suggest that as many as three of every five females with a reproductive disorder will have high prolactin. 

Symptoms of hyperprolactinemia in females include:

• Irregular periods
• Absent periods
• Loss of libido (sex drive)
• Galactorrhea (the production of breast milk when you are not pregnant or breastfeeding)
• Infertility (due to the absence of ovulation)
• Hot flashes
  
• Vaginal dryness
• Weight gain
• Breast tenderness
  
• Acne
  
• Hirsutism (excess body and facial hair growth)
  

High Prolactin Symptoms in Males

Symptoms of hyperprolactinemia in males are often harder to recognize because they tend to be more subtle and non-specific than those experienced by females.

Symptoms of hyperprolactinemia in males include:

• Loss of libido
• Erectile dysfunction
• Infertility (due to decreased sperm production)
• Gynecomastia (abnormal breast enlargement)
• Galactorrhea (uncommon but possible)
  

Mood Symptoms of Hyperprolactinemia

Our moods are greatly influenced by hormones, including sex hormones like estrogen and testosterone. Hyperprolactinemia has a cause-and-effect relationship with these and other hormones.

In some cases, hyperprolactinemia may be the result of diseases of the ovaries or testicles, both of which produce estrogen and testosterone. In other cases, dysfunction of the hypothalamus, pituitary gland, or adrenal glands (HPA axis) can lead to an imbalance of sex hormones and other hormones that influence moods (like dopamine).

These changes can significantly alter moods in people with hyperprolactinemia. The severity of symptoms tends to increase with the level and duration of prolactin increases.

Mood symptoms related to hyperprolactinemia include:

• Anxiety
• Depression
• Irritability and hostility
• Somatization (physical symptoms arising from psychological distress, such as headaches, chest pain, back pain, nausea, and fatigue)
• Psychosis (a loss of touch with reality)

What Causes High Prolactin Levels?

The secretion of prolactin by the pituitary gland (a pea-sized body organ located at the base of the brain) is regulated by two hormones:

• Dopamine: This is a hormone produced by the adrenal glands that slows down prolactin production.
• Thyrotropin-releasing hormone (TRH): This is a hormone produced by the hypothalamus which increases prolactin production.

When prolactin levels are abnormally high, it is due to conditions that either decrease the production of dopamine, increase the production of TRH, or both. This may be caused by diseases or disorders that directly or indirectly affect the function of the HPA axis.

The most common cause of hyperprolactinemia is a type of pituitary adenoma (tumor) known as a prolactinoma. This benign tumor tends to appear for no known reason, although there are a few types that can be inherited from a parent.

Other causes of hyperprolactinemia include:

• Benign brain tumors: These include non-cancerous tumors like pituitary adenomas, craniopharyngioma, and meningioma.
• Trauma: This includes injuries incurred during surgery or radiation of the pituitary gland, adrenal glands, or hypothalamus.
• Hypothyroidism: This occurs when the thyroid gland doesn't produce enough thyroid hormones, causing an increase in TRH.
• Cushing’s syndrome: This is a disorder caused by abnormally high levels of the stress hormone cortisol.
• Systemic diseases: These are whole-body diseases like chronic kidney disease (CKD) and liver disease that directly or indirectly affect the endocrine (hormonal) system.
• Medications: These include drugs that increase the secretion of prolactin, including certain antidepressants, antipsychotics, opioids, estrogen, H2 blockers, and high blood pressure medications.
  
• Acromegaly: This is a hormonal disorder in which the pituitary gland produces too much growth hormone (GH), upsetting the balance of other hormones.
• Lymphocytic hypophysitis: This is an autoimmune disease that causes inflammation of the pituitary gland.
• Rathke’s cyst: This is fluid-filled growth that develops between parts of the pituitary gland.
• Cancer: These include dysgerminoma (a type of ovarian cancer) or brain metastases (cancers that have spread to the brain).
  

Diagnosis of High Prolactin

Prolactin is measured with a blood test performed in a fasting state (meaning you will not have eaten since the night before the test).

The results are interpreted based on a reference range of values, meaning a high and low value between which the results are considered normal. The values are described in either nanograms per milliliter of blood (ng/mL) or micrograms per liter of blood (µg/L)

Normal prolactin levels are generally defined as follows:

• Males: Less than 20 ng/mL (20 µg/L) 
• Females: Less than 25 ng/mL (25 µg/L)
• Pregnant females: Between 80 and 400 ng/mL (80 and 400 µg/L)

Anything above these values in a fasting state is considered hyperprolactinemia.

Your healthcare provider may also order an imaging test called magnetic resonance imaging (MRI) that may be able to detect a pituitary adenoma or pituitary inflammation.

High Prolactin Treatment

High prolactin levels without symptoms (asymptomatic) may not require treatment. The goal of hyperprolactinemia treatment is to restore normal prolactin levels and relieve symptoms. This can often be done by treating the underlying cause. For example:

• Drug-induced hyperprolactinemia is treated by either lowering the dose or prescribing a different medication.
• Hypothyroidism-related high prolactin is treated with synthetic thyroid hormone.

Other treatments for hyperprolactinemia include:

• Dopamine agonists such as Dostinex (cabergoline) and Parlodel (bromocriptine). Dopamine agonists work to treat hyperprolactinemia by increasing the brain’s receptiveness to dopamine. The dosage is gradually increased until prolactin levels are normalized.
• Hormone therapy, including estrogen or testosterone, may be prescribed for hyperprolactinemia associated with long-term hypogonadism.
• Surgery may be needed to treat a pituitary adenoma or other tumor.
• Radiation therapy may be used to treat prolactinomas that do not respond to medication or surgery. However, this treatment is rarely needed.

After successful treatment, your healthcare provider may want you to have regular blood tests to ensure that prolactin levels stay within a normal range. If your condition was caused by a tumor, you may need another MRI to monitor for the reappearance or enlargement of the growth.

Summary

Symptoms of high prolactin levels include irregular periods, loss of sex drive, sexual dysfunction, heavy menstrual bleeding, weight gain, anxiety, depression, and psychosis.

High prolactin levels (hyperprolactinemia) can be caused by many different things, including diseases and disorders of the pituitary gland, adrenal glands, thyroid gland, brain, kidney, liver, ovaries, and testicles. Certain medications can also cause higher prolactin levels.

Hyperprolactinemia is diagnosed with a blood test. The treatment can vary by the underlying cause, but the ultimate goal is to restore prolactin to normal levels.