Introduction:
Hyperprolactinemia is a state that occurs due to increased levels of a hormone called prolactin in the bloodstream. The condition is a normal occurrence during pregnancy and breastfeeding; however, when it occurs during other times due to disease or the use of certain medicines, it must be addressed and treated. Hyperprolactinemia can affect both men and women, causing symptoms like menstrual disturbances, infertility, and breast milk production.
What Is Prolactin?
Prolactin is produced by the pituitary gland, a small pea-sized gland located at the base of the brain. Also called lactotropin, the hormone helps in the development of mammary glands in the breast tissue, milk production, and lactation. Small amounts of prolactin are also produced by the uterus, nervous system, and immune system. Apart from promoting breast milk production, prolactin also suppresses other pituitary hormones like luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thereby decreasing the levels of estrogen (in women) and testosterone (in men) affecting fertility. Prolactin levels are low in non-pregnant, non-lactating people and in males. Elevated levels are common in pregnant or breastfeeding mothers.
The normal prolactin values include:
-
In Males: Less than 20 ng/mL.
-
Non-pregnant and Non-lactating Women: Less than 25 ng/mL.
-
In Pregnant or Breastfeeding Women: 80 to 400 ng/mL.
All the above units of measurement are nanograms per milliliter (ng/mL).
Who Does Hyperprolactinemia Affect More Commonly?
Hyperprolactinemia affects people below the age of 40. It is more common in females when compared to males and very rare in children.
How Is Prolactinoma Different From Hyperprolactinemia?
Prolactinoma is a benign (harmless) tumor of the pituitary gland which leads to excess production of the hormone prolactin.
Hyperprolactinemia occurs due to increased blood levels of prolactin. Apart from prolactinomas being the reason, other medical conditions or the use of certain medicines can also lead to hyperprolactinemia.
What Are the Causes of Hyperprolactinemia?
The causes of hyperprolactinemia include:
-
Prolactinoma.
-
Certain health conditions.
-
Certain medicines.
-
Other tumors of the pituitary gland.
Sometimes there can be no particular cause for hyperprolactinemia. This condition is called idiopathic hyperprolactinemia. They usually subside on their own without any treatment.
Prolactinomas: A prolactinoma is a harmless tumor of the pituitary gland which results in excess production of prolactin. It is the most common cause of hyperprolactinemia.
Health Conditions:
Certain health conditions apart from prolactinomas can also cause high prolactin levels in the blood, which include:
- Kidney diseases.
- Hypothyroidism is a condition due to a decrease in the production of thyroid hormones.
- Shingles are a viral infection that causes painful blisters and rashes on the skin.
- Polycystic ovary disease is a hormonal disorder that affects women of childbearing age.
- Cushing’s syndrome is a disorder occurring due to high levels of the hormone cortisol.
- Nelson syndrome is a condition occurring in patients after treatment for Cushing’s syndrome due to the removal of both adrenal glands.
- Chest wall injuries like fractured ribs or breastbone or bruising of the lungs.
Medications:
The brain releases a chemical called dopamine, which suppresses the production of prolactin in the body. Medicines that affect dopamine levels in the body can cause an increase in prolactin levels, which include:
-
Contraceptives or birth control pills.
-
Pain relievers that contain opioids.
-
Medicines like Metoclopramide are used to treat nausea.
-
Antipsychotic medications like Haloperidol and Risperidone.
-
Medicines for the treatment of menopause symptoms like estrogen therapy.
-
High blood pressure medications like Methyldopa or Calcium channel blockers.
-
Medicines for the treatment of heartburn and GERD (gastroesophageal reflux disease).
Stopping the suspected medicine can return the prolactin levels to normal within three to four days. However, change or stoppage of medicines has to be done after the advice of a doctor.
Other Tumors:
Large tumors near the pituitary gland prevent dopamine that suppresses prolactin from reaching the pituitary gland.
What Are the Signs and Symptoms of Hyperprolactinemia?
As hyperprolactinemias occur more commonly in women, the following symptoms are noted, which include:
-
Irregular or no periods.
-
Discomfort and pain during sex due to dry vagina.
-
Breast milk production in non-pregnant and non-lactating females.
-
Pain in the breast.
Symptoms in males include:
-
Low levels of the hormone testosterone.
-
Gynecomastia or enlarged breast tissue.
-
Erectile dysfunction (inability to get and maintain an erect penis during sexual activity).
-
Decreased body hair and muscle mass.
As increased prolactin levels do not cause obvious symptoms in men, headaches and changes in vision that occur due to pituitary tumors may be the first sign of hyperprolactinemia.
Symptoms that are common in both males and females include:
-
Infertility.
-
Loss of interest in sex.
-
Decrease in bone mass.
How Is Hyperprolactinemia Diagnosed?
-
Diagnosis of hyperprolactinemia is made based on blood test reports which indicate high prolactin levels. The doctor may advise repeating the test in case of high blood prolactin levels, probably after fasting for at least eight hours.
-
Doctors may suggest an MRI (magnetic resonance imaging) scan in order to look for any growths or tumors in the pituitary gland or the surrounding structures. MRI scan uses magnetic fields and radio waves to produce detailed images of internal body parts.
Additional blood and imaging tests may be required to determine other causes and treat the same.
How Is Hyperprolactinemia Treated?
-
Treatment of hyperprolactinemia depends on the cause. Treatment is not required in cases of few symptoms.
-
Patients with prolactinomas, which is the most common cause of hyperprolactinemia, require treatment in the form of medications, surgery or radiation therapy, or a combination of the above.
Treatment options for prolactinomas include:
Medication:
-
Medicines called Dopamine agonists are used to control the prolactin levels in the blood. They also help to shrink the size of tumors, thereby reducing the effects of pressure on the surrounding tissues and nerves.
-
Cabergoline, Bromocriptine, and Quinagolide are the most commonly used medications.
-
Common side effects of these medicines include dizziness, nausea, and vomiting.
-
The doctor prescribes medications for two years. Treatment is started with a low dosage, and once the patient's body gets accustomed to the medicines, the dosage is gradually increased.
-
Fertility is restored once the treatment is started. However, the patient is asked to avoid the medication during pregnancy, and regular monitoring of the prolactin levels is recommended.
Surgery:
-
Surgery is considered in cases where the patient has side effects due to medicines, drug interactions (with other drugs that the patient is using), or a large tumor.
-
The two types of surgeries that are used to treat prolactinomas include:
-
Transsphenoidal Surgery: This is the most commonly employed technique. Access to the tumor is achieved through the nasal cavity. Therefore, complications are less in the transsphenoidal approach.
-
Transcranial Surgery: Larger tumors that are difficult to remove through transsphenoidal or nasal surgery are removed by the surgeon through surgery in the upper part of the skull.
-
Radiation:
-
Therapy with radiation is suggested in cases that do not respond to medicines or surgery. However, it is a rarely employed technique. A single dose or multiple doses of radiation are decided based on the size of the tumor and the prolactin levels in the blood.
If the cause of high blood prolactin levels is due to prescribed medicines, doctors may recommend alternative options for the medicines. Hyperprolactinemia that occurs due to hypothyroidism can be managed by prescribing synthetic thyroid hormones, which bring the prolactin levels back to normal.
Can Hyperprolactinemia Be Prevented?
Hyperprolactinemia cannot be prevented. However, patients whose first-degree relatives (parent or sibling) are diagnosed with prolactinoma or MEN type 1 can go for genetic testing to know whether they have the condition as well.
Conclusion:
Hyperprolactinemia occurs due to increased levels of the hormone prolactin in the blood. The condition has a positive outlook and is treatable. In most cases, prolactinomas, which are the common cause, can be managed with medications or surgery, leading to a reversal of symptoms. Though the condition is not life-threatening, it can affect the quality of life due to issues like irregular periods and infertility. Men can face social embarrassment due to symptoms like enlarged breasts or hair loss. Consultation with a health care provider can always help the patients recover positively.