In normal cases, high prolactin levels are observed in nursing and pregnant women. Prolactin is produced by the pituitary gland. This gland is a small structure located in the brain, and along with prolactin, it secretes other hormones as well. The primary function of the prolactin hormone is to enhance the development of the breasts and to initiate lactation or breastfeeding.

A blood test to check for high prolactin levels is usually prescribed in the case of irregular menstrual periods, breast milk leakage (especially if the woman is not nursing a baby), and infertility.

Read on to know more about the symptoms, causes, diagnosis, and treatment of high prolactin levels.

Causes
High prolactin levels or hyperprolactinemia is caused by multiple factors, including disease of the hypothalamus, kidney disease, pituitary tumor, hypothyroidism, and Cushing’s disease. Additionally, certain medications can also lead to high prolactin levels in the body. Prolactin levels are regulated by dopamine. So, medications that affect dopamine levels can interfere with prolactin levels as well. Medications that are prescribed for gastrointestinal and psychiatric disorders may lead to high prolactin levels. These medications include tricyclic antidepressants, antipsychotics, blood pressure medication, metoclopramide, verapamil, acid blockers, estrogens, serotonin reuptake inhibitors, phenothiazines, risperidone, and anti-nausea medications. Chest trauma and prolonged excessive stress may also lead to elevated levels of prolactin.

Symptoms
In most cases, the symptoms of hyperprolactinemia or high prolactin levels are nonexistent. However, some women may experience white milk leaking from the nipples (even when they are not nursing a baby), loss of libido, painful or uncomfortable intercourse, hot flashes, and vaginal dryness. There might be absent, infrequent, or irregular periods. Additionally, some women may also have a lot of acne and excessive body and facial hair growth or hirsutism. In some cases, high prolactin levels may also lead to infertility.

Diagnosis
Prolactin levels are measured through a routine blood test. It is recommended that women who are testing for high prolactin levels should avoid intercourse and breast stimulation the night before they under the test. This is essential because there are multiple factors that may affect the blood values and lead to incorrect test results.
In case high prolactin levels are detected in the first test, a doctor may repeat the test. The second test is done with prior fasting of at least 8 hours. The doctor may also want to check for pituitary growth or damages to the surrounding tissues. In such a case, magnetic resonance imaging or MRI may be prescribed. Moreover, additional blood tests may be recommended to check for the production of other pituitary hormones. This will help in ruling out disorders that cause symptoms similar to high prolactin levels.

Treatment
The goal of any treatment is to restore the high prolactin levels to normal. This is usually done with the use of prescription medications such as dopamine agonists. In extreme cases, surgery may also be recommended to remove or reduce a tumor in the pituitary gland. Once the high prolactin levels have been lowered, it is recommended to regularly undergo a blood test to monitor the prolactin levels. In some cases, frequent MRI scans may also be recommended to monitor the size of the tumor and check for growth.