Symptoms and Treatment of Hyperprolactinemia

Hyperprolactinemia occurs when you have high levels of prolactin in your blood. Prolactin is a hormone produced by the pituitary gland that is primarily responsible for milk production (lactation) and the development of mammary glands in the breast.

While hyperprolactinemia is considered normal during pregnancy and breastfeeding, it can occur at other times due to disease or medication use. Hyperprolactinemia can affect both females and males, resulting in irregular menstrual periods and erectile dysfunction, among other things.

This article describes the causes and symptoms of hyperprolactinemia, including how this hormonal condition is diagnosed and treated.

What Is Prolactin?

Prolactin, also known as lactotropin and mammotropin, is a hormone produced in the pituitary gland.

Prolactin plays many roles in the human body, although it is best known for its role in stimulating breast milk production. During the latter part of pregnancy when progesterone levels start to fall, levels of prolactin will increase, causing enlargement of the mammary glands. These are the glands in the breast that produce milk.

During pregnancy and breastfeeding, hyperprolactinemia is not only considered normal but essential to fetal development.

In females, prolactin is also responsible for:

• Stimulating the production of surfactants that enable smooth respiration in the developing lungs of the fetus
• Promoting the development of neurons (nerve cells) in the fetus, referred to as neurogenesis
• Stimulating the production of cells that produce myelin, a type of protein that covers and protects neurons, ensuring smooth nerve transmission
• Supports the innate immune function in the fetus and throughout life
• Maternal sensitivity (a mother's ability to perceive the meaning behind an infant's behavioral signals)

Prolactin in males supports the innate immune response but has no other function. Even so, maintaining normal levels of prolactin is essential to normal sexual function. In the same way that prolactin levels are influenced by progesterone and estrogen levels in females (and vice versa), prolactin levels are influenced by testosterone levels in males (and vice versa).

What Causes Hyperprolactinemia in Females and Males?

Hyperprolactinemia can develop due to physiological, pathological, or pharmaceutical causes. In some cases, high prolactin levels are considered normal. In other cases, hyperprolactinemia is a serious medical concern.

Physiological Causes

Prolactin has a relatively short half-life, between 20 and 50 minutes, meaning that it needs to be replenished regularly to keep levels normal, Any condition that "uses up" prolactin will cause hyperprolactinemia.

There are different physiological reasons why this might occur, including:

• Pregnancy
• Breastfeeding
• Exercise
• Physical or psychological stress
• Seizures
• Sexual intercourse

Pathological Causes

Prolactin levels may be elevated for any number of reasons. One of the more common causes is the formation of a benign tumor on the pituitary gland. This noncancerous growth, known as prolactinoma, directly secretes excessive prolactin while suppressing estrogen and testosterone levels.

Diseases affecting a portion of the brain called the hypothalamus can also cause hyperprolactinemia. The hypothalamus is the organ in the brain that links to the pituitary gland. An increase in prolactin can often be directly linked to a tumor, trauma, or infection of the hypothalamus.

Other causes include:

• Hypothyroidism (low thyroid hormone levels)
• Chronic kidney disease
• Acromegaly (an overactive pituitary gland)
• Cushing's disease (a disorder that causes the overproduction of the hormone cortisol)

Pharmaceutical Causes

Many drugs can cause prolactin levels to spike. They do so by altering the production of different hormones that influence prolactin levels, including estrogen and dopamine.

These include:

• Estrogen therapy
• Tricyclic antidepressants
• Antipsychotics
• Antihypertensives
• Antiemetic (anti-nausea) drugs
• H2 antihistamines
• Dilantin (phenytoin)

What Are the Symptoms of Hyperprolactinemia?

The symptoms of hyperprolactinemia in females can vary. When occurring outside of pregnancy or breastfeeding, they may include:

• Infertility
• Galactorrhea (abnormal lactation)
• Infrequent or irregular periods
• Amenorrhea (disappearance of periods)
• Loss of libido (sex drive)
• Breast pain

When occurring in males, the symptoms typically involve sexual dysfunction and/or pain associated with the formation of prolactinoma. Common signs and symptoms include:

• Erectile dysfunction
• Gynecomastia (development of breast tissue)
• Galactorrhea
• Infertility
• Loss of libido

How Hyperprolactinemia Is Diagnosed

The diagnosis of hyperprolactinemia involves a routine blood test to check prolactin levels. If the levels are elevated, the doctor may want to repeat the test, this time after you fast for at least eight hours.

Normal ranges for prolactin in your blood are as follows:

• Males: 2 to 18 nanograms per milliliter (ng/mL)
• Non-pregnant females: 2 to 29 ng/mL
• Pregnant females: 10 to 209 ng/mL

A magnetic resonance imaging (MRI) scan may be ordered to look for evidence of a pituitary growth or damage to surrounding tissues. Blood tests to evaluate other hormone levels may be useful in ruling out any other possible causes of the symptoms.

What Is the Best Treatment for Hyperprolactinemia?

The goal of treatment is to return prolactin to normal levels. There are a number of standard options to achieve this:

• The medications Parlodel (bromocriptine) and Dostinex (cabergoline) are known to be effective in reducing prolactin levels and shrinking pituitary tumors.
• Surgery may sometimes be used to remove a pituitary tumor if the medications are not working or are poorly tolerated.
• Radiation, while rarely used, may be suggested if the medicines and surgery have not been effective.
• Hypothyroidism can be treated with synthetic thyroid hormone, which should bring prolactin levels down.
• If high prolactin levels are caused by prescription drugs, substitute medications may be prescribed.

Summary

Hyperprolactinemia occurs when prolactin levels are high in females or males. Although high prolactin is normal during pregnancy and breastfeeding, high levels outside of pregnancy may be the result of diseases or drugs that directly or indirectly affect the pituitary gland.

Hyperprolactinemia can be diagnosed with a blood test. If high prolactin is the result of a disease, medications or surgery may be needed to correct the issue.