What Is Hyperprolactinemia?

Overview

Hyperprolactinemia is characterized by elevated levels of the hormone prolactin in the bloodstream. Prolactin is responsible for stimulating the production of breast milk during and after pregnancy. The condition arises from the presence of a noncancerous growth, known as a prolactinoma, in the pituitary gland. This gland is responsible for regulating prolactin production. The precise factors leading to the development of prolactinomas remain unclear, as they seem to manifest spontaneously and are not hereditary. Both men and women can be affected by these tumors. In certain instances, tumors unrelated to prolactinomas, located in or near the pituitary gland, can obstruct the transmission of dopamine from the brain to the cells that secrete prolactin. This obstruction results in hyperprolactinemia. Another potential cause of hyperprolactinemia is hypothyroidism, a condition characterized by an underactive thyroid gland.¹

Causes of hyperprolactinemia

The primary cause of hyperprolactinemia is excessive secretion of prolactin from the pituitary gland, which is responsible for producing various hormones that circulate throughout the body. In females, elevated prolactin levels have been associated with physical or psychological stress, pregnancy, and nipple stimulation.

Both males and females can experience increased prolactin levels due to chronic kidney disease and hypothyroidism, a condition characterized by insufficient production of thyroid hormone. Additionally, certain medications and medical conditions can contribute to heightened prolactin levels.

Furthermore, a noncancerous growth known as a prolactinoma, located on the pituitary gland, can lead to excessive prolactin production, thereby interfering with normal bodily functions.²

Signs and symptoms of hyperprolactinemia

Certain individuals with hyperprolactinemia may exhibit mild or no symptoms, remaining asymptomatic.

Hyperprolactinemia can manifest the following symptoms for anyone affected:

• Infertility
• Decreased sexual desire
• Reduced bone density
• Milky discharge from the nipples when not pregnant or breastfeeding (galactorrhea)

In individuals assigned female at birth (AFAB), hyperprolactinemia symptoms may include:

• Irregular menstruation unrelated to menopause, such as irregular periods (menstruation) or the absence of periods (amenorrhea)
• Pain or discomfort during sexual intercourse caused by vaginal dryness

For individuals assigned male at birth (AMAB), typical symptoms of hyperprolactinemia comprise:

• Erectile dysfunction (ED)
• Decreased testosterone levels
• Enlarged breast tissue (gynecomastia)³

Management and treatment for hyperprolactinemia

The approach to treating hyperprolactinemia varies depending on its underlying cause. Some individuals with elevated prolactin levels, yet minimal or no symptoms, may not require treatment.

For prolactinomas (the primary cause of hyperprolactinemia), the following treatment options are available:

• Medication: Dopamine agonists are commonly prescribed to regulate prolactin levels and effectively shrink prolactinoma tumors. This form of treatment is the most prevalent for prolactinomas
• Surgery: In cases where medication fails to reduce the size of the prolactinoma, surgical removal may be necessary
• Radiation therapy: In rare instances where medication and/or surgery are unsuccessful in lowering prolactin levels, radiation therapy may be considered as a third-line treatment for prolactinomas
• In the case of hyperprolactinemia caused by hypothyroidism, treatment involves administering synthetic thyroid hormone, which should help normalize prolactin levels

If the use of prescribed medications contributes to hyperprolactinemia, healthcare providers may prescribe alternative medications that either do not elevate prolactin levels or have a lesser impact on their increase.³

Diagnosis of hyperprolactinemia

The diagnosis of hyperprolactinemia typically relies on an evaluation of the patient's symptoms, medical history, and a thorough physical examination. Blood tests are performed to measure the concentration of prolactin in the bloodstream. In cases where abnormal prolactin levels are detected, healthcare professionals may repeat the blood test to ensure that medications are not responsible for the elevation. Additionally, imaging techniques like magnetic resonance imaging (MRI) scans of the brain may be utilise to aid in the diagnosis process.²

FAQs

Can hyperprolactinemia be prevented

Regrettably, there are no preventive measures known to avoid hyperprolactinemia.

The sole identified risk factor associated with the development of a prolactinoma, which is the most common cause of hyperprolactinemia, is having an inherited condition known as multiple endocrine neoplasia (MEN) type 1.

If you have a first-degree relative (such as a sibling or parent) with this condition, it might be advisable to undergo genetic testing to determine if you have inherited it as well. This screening can aid in the early detection of prolactinomas and their timely management.³

How common is hyperprolactinemia

Hyperprolactinemia is a condition that impacts less than 1% of the overall population. The primary factor contributing to hyperprolactinemia is the presence of a benign tumor called a prolactinoma, which releases excessive prolactin. Prolactinoma occurrence rates are estimated at approximately 30 cases per 100,000 individuals assigned female at birth and 10 cases per 100,000 individuals assigned male at birth.³

Who are at risks of hyperprolactinemia

Hyperprolactinemia primarily affects individuals who are younger than 40 years old. People assigned female at birth (AFAB) have a higher likelihood of developing hyperprolactinemia compared to people assigned male at birth (AMAB). It is uncommon for hyperprolactinemia to occur in children.³

When should I see a doctor

If you are encountering symptoms suggestive of hyperprolactinemia, such as infertility and decreased libido, it is advisable to consult with your healthcare professional. They can perform a straightforward blood test to determine if your prolactin levels are elevated.³

Summary

The prognosis for hyperprolactinemia is typically positive, with treatment for prolactinomas, the primary underlying cause, often yielding positive results.

While hyperprolactinemia itself is not considered life-threatening, it can lead to complications such as infertility and menstrual irregularities. Consequently, seeking appropriate treatment is crucial for individuals diagnosed with hyperprolactinemia to address and manage these potential issues.³

References

1. Hyperprolactinemia. John Hopkins Medicine. 2019.
2. Hyperprolactinemia. Yale Medicine. 2023.
3. Hyperprolactinemia: what it is, causes, symptoms & treatment. Cleveland Clinic. 2022.