A person with hyperprolactinemia has unusually high levels of the hormone prolactin. This hormone is made by the pituitary gland and is most commonly associated with breastfeeding women, as it helps in the production of breast milk.

Men and women who aren’t pregnant make prolactin, too, but in smaller amounts.  Scientists aren’t sure what role it plays in these people.

When prolactin levels rise substantially in men, they can significantly affect sexual function. Research has shown that severe hyperprolactinemia (usually greater than 35 ng/mL) has been linked to low libido and delayed ejaculation in men.

High prolactin might also interfere with testosterone production and erections.

Some causes of hyperprolactinemia include the following:

• Problems with the pituitary gland, such as tumors or diseases
• Hypothyroidism (an underactive thyroid gland)
• Head trauma
• Chronic renal failure
• Herpes zoster (shingles)
• Epileptic seizures
• Certain medications, such as antipsychotics, opiates, and some antidepressants

Hyperprolactinemia may be treated in different ways. Doctors usually try to determine the underlying cause and treat that first. Medications may be prescribed. Surgery may be necessary if there are tumors on the pituitary gland.