1. What is Prolactin?
Prolactin is a hormone produced by your pituitary gland, a pea-sized organ found at the base of the brain. The pituitary gland is called the master gland because it makes hormones that control levels of other hormones. Though prolactin plays a role in the growth and development of breasts in females, its primary function is in milk production after a child is born. That’s why high prolactin levels are normal during pregnancy and breastfeeding. Prolactin also affects the levels of sex hormones (estrogen and testosterone) in both women and men.
2. What is hyperprolactinemia?
Hyperprolactinemia is a condition in which a person has higher-than-normal levels of the hormone prolactin in the blood.
3. What are the symptoms of Hyperprolactinemia?
Symptoms can vary from person to person, but may include:
No menstrual periods or irregular periods
Breast milk secretion in the absence of Pregnancy/Breastfeeding- A condition called Galactorrhea
Vaginal dryness, making sex painful
Low testosterone levels
Progressive loss of libido
Low sperm count
Breast enlargement in males called as Gynecomastia
Decreased muscle mass and body hair
In addition hyperprolactinemia in both males and females may results in early loss of bone mass leading to osteoporosis.
4. What causes hyperprolactinemia?
Prolactin levels increase as a result of:
A. Prolactinoma- Growth or tumor on the pituitary gland called a prolactinoma, which produces high levels of prolactin. These tumors can be large or small and are usually benign, meaning they are not cancerous. Large tumors can also cause headaches, vision problems, or both. Prolactinomas are more common in women than in men and rarely occur in children.
B. Certain prescription medicines can also increase prolactin levels. These include medicines for:
Drugs for acidity, heartburn or vomiting (domperidone, metoclopramide)
Antihypertensive (such as calcium-channel blockers and methyldopa)
Antipsychotics such as risperidone and haloperidol
C. Other causes include:
Hypothyroidism or underactive thyroid
Chest-wall injuries or other conditions that affect the chest wall
Other tumors and diseases affecting the pituitary gland, or radiation treatment for tumors on or near the pituitary
Chronic liver and kidney diseases
Sometimes, a cause for hyperprolactinemia cannot be found.
5. How is hyperprolactinemia diagnosed?
A blood test is used to detect excess prolactin. If prolactin levels are high, more tests are usually done like blood levels of thyroid hormone, liver and kidney function test. A medication history is very important to rule out drug induced hyperprolactinemia. Pregnancy should also be ruled out in case of amenorrhea. If a prolactinoma is suspected, an MRI (magnetic resonance imaging) of the pituitary is often the next step. You should seek the opinion of Endocrinologist for workup/treatment.
6. What is the treatment for hyperprolactinemia?
Treatment is based on the cause. Options for treating tumors include:
Medications- Bromocriptine and cabergoline are often prescribed to decrease prolactin production and decrease tumor growth. Medicines work well for most people with prolactinomas. Dose and duration of treatment will be decided by your Doctor/Endocrinologist.
Surgery to remove a tumor. Surgery is rarely required if medicines have not been effective or if the tumor is affecting vision.
Radiation. Very rarely radiation is used to shrink the tumor.
Bromocriptine and cabergoline are also used to treat hyperprolactinemia with no known cause. Hypothyroidism is treated with synthetic thyroxine. If high prolactin levels are caused by prescription medications, other types of medications can be explored in discussion with your doctor.