From the Guidelines
Elevated prolactin, or hyperprolactinemia, is a condition where the level of prolactin hormone in the blood is higher than normal, requiring age-specific and sex-specific prolactin reference ranges and exclusion of confounding conditions such as hypothyroidism, renal and/or hepatic impairment, and use of medications that cause hyperprolactinaemia 1. To assess hyperprolactinaemia, a single prolactin measurement taken at any time of the day is sufficient, but modestly elevated serum prolactin levels should be investigated by serial measurements over time to exclude the effect of stress and prolactin pulsatility 1.
Key Points to Consider
- Serum prolactin concentrations vary with age and sex, with highest levels in the first 2 years of life, falling to a nadir in mid-childhood, and rising again in adolescence 1.
- Diagnostic serum prolactin concentrations for prolactinomas are usually above 4,000 mU/l (188 μg/l), although lower levels can be seen in patients with microprolactinomas 1.
- Unexplained, persistently mildly or moderately elevated prolactin in blood samples taken after rest could be due to the stalk effect (disconnection hyperprolactinaemia, pituitary stalk compression from mass lesions disrupting the dopaminergic inhibition of lactotroph cells) 1.
Causes and Symptoms
- Causes of elevated prolactin include pituitary tumors (prolactinomas), certain medications, hypothyroidism, kidney or liver disease, chest wall trauma, or stress.
- Symptoms in women may include irregular or absent periods, infertility, vaginal dryness, and inappropriate milk production, while men might experience decreased libido, erectile dysfunction, infertility, or breast enlargement.
Diagnosis and Treatment
- Diagnosis requires blood tests, possibly an MRI of the brain, and thyroid function tests to determine the cause of elevated prolactin 1.
- Treatment depends on the cause and may include dopamine agonist medications, addressing underlying conditions, or changing medications 1.
From the Research
Definition of Elevated Prolactin
Elevated prolactin, also known as hyperprolactinemia, refers to a condition where the level of prolactin in the blood exceeds the normal range. According to 2, when prolactin levels exceed 80-100 ng/ml, a pituitary adenoma must be ruled out by MRI.
Causes of Elevated Prolactin
The causes of elevated prolactin can be varied, including:
- Pituitary adenomas, which are the most common cause of chronic hyperprolactinemia 3
- Pregnancy
- Primary hypothyroidism
- Drugs that elevate serum prolactin levels, such as antipsychotics 2
- Other endocrine disorders
Symptoms of Elevated Prolactin
The symptoms of elevated prolactin can include:
- Hypogonadism
- Infertility
- Galactorrhea
- Osteopenia
- Mass effects of the tumor, such as visual disturbances 3, 4
- Menstrual irregularity or amenorrhea in women 4
- Visual disturbance in men 4
Treatment of Elevated Prolactin
The treatment of elevated prolactin depends on the underlying cause and can include:
- Dopamine agonists, which are the treatment of choice for most patients with prolactinomas 3, 5, 6
- Switching to a less hyperprolactinemic antipsychotic 2
- Sex steroid supplementation 2
- Surgery, which is usually reserved for patients who are intolerant of or resistant to dopamine agonists or when hyperprolactinemia is caused by non-prolactin-secreting tumors compressing the pituitary stalk 3, 5
- Radiation therapy, which may be considered in some cases 5