Galactorrhea is the production of breast milk not associated with pregnancy or breastfeeding. It can occur in women, even those who have never been pregnant or have gone through menopause, and it can also affect men. While unexpected milk discharge can be concerning, galactorrhea is a sign of an underlying issue, always warranting medical investigation.
The Role of Prolactin
The hormone prolactin, primarily produced by lactotroph cells in the anterior pituitary gland at the base of the brain, is central to milk production. Prolactin stimulates mammary glands to produce milk. Its secretion is inhibited by dopamine from the hypothalamus.
Thyrotropin-releasing hormone (TRH) also stimulates prolactin release. The body tightly regulates prolactin levels through these factors. Disruption of this balance can lead to elevated prolactin levels, known as hyperprolactinemia, which may result in galactorrhea.
Hormonal Imbalances and Medical Conditions
Several medical conditions and hormonal imbalances can contribute to galactorrhea by affecting prolactin levels. One common cause is a prolactinoma, a benign (non-cancerous) tumor of the pituitary gland that produces excessive prolactin. These tumors can also cause symptoms such as irregular menstrual periods, reduced sexual desire, headaches, and changes in vision.
Another condition linked to galactorrhea is hypothyroidism, which occurs when the thyroid gland is underactive. An underactive thyroid leads to increased TRH production, and this elevated TRH can stimulate the pituitary gland to release more prolactin.
Conditions affecting organ function, such as chronic kidney disease, can also lead to elevated prolactin levels. Impaired kidney function reduces the body’s ability to clear prolactin from the bloodstream, causing it to accumulate.
Similarly, liver diseases, particularly severe forms like cirrhosis, may also be associated with increased prolactin. Impaired liver function can affect hormone metabolism or clearance, potentially leading to higher prolactin.
Medication-Induced Lactation
Many pharmaceutical agents can cause galactorrhea as an unintended side effect. These medications often interfere with prolactin regulation by blocking dopamine’s action or directly stimulating prolactin release.
Certain antipsychotic medications, such as risperidone and haloperidol, block dopamine receptors, leading to increased prolactin levels. Antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants, have also been associated with hyperprolactinemia. Some blood pressure medications, like verapamil and methyldopa, can also contribute to this effect. Opioids, used for pain management, can elevate prolactin by decreasing dopamine release. Additionally, certain heartburn medications, such as metoclopramide and cimetidine, function as dopamine D2 receptor blockers, which can result in increased prolactin secretion.
Discontinuing the offending drug under medical supervision often resolves medication-induced galactorrhea.
Other Contributing Factors and Medical Consultation
Beyond hormonal imbalances and medications, several other factors can contribute to galactorrhea. Physical stimulation of the breasts or nipples, whether from frequent self-examination, tight clothing, nipple piercing, or sexual activity, can trigger prolactin release. Chronic stress is another potential factor, as it can influence overall hormonal balance, including prolactin levels. Certain herbal remedies or supplements, such as fennel, anise, or fenugreek seed, have also been reported to induce lactation. In some cases, no clear cause is identified, a situation referred to as idiopathic galactorrhea, which may indicate that the breast tissue is particularly sensitive to normal levels of prolactin.
Anyone experiencing galactorrhea should consult a healthcare professional for diagnosis. A doctor will perform a physical examination for nipple discharge and breast lumps. A detailed medical history, including medications, is also important.
Diagnostic steps often include blood tests to measure prolactin levels, thyroid-stimulating hormone (TSH), and kidney function. A pregnancy test may also be conducted. If prolactin levels are elevated, magnetic resonance imaging (MRI) of the pituitary gland may be ordered to check for tumors. If breast changes are noted, mammography or ultrasound might be recommended. Self-diagnosis is not recommended due to the wide range of potential causes.