Galactorrhea

Galactorrhea is the nonpregnancy-related discharge of milk-like fluid from the nipples. It can be bilateral or unilateral and may occur with or without breast fullness or mastalgia. Galactorrhea can be a physiologic finding or a symptom of an underlying condition causing hyperprolactinemia or nipple stimulation.

Common causes include physiologic factors (pregnancy, lactation cycles, sexual stimulation), drugs that raise prolactin levels (dopamine antagonists such as certain antipsychotics and antiemetics; antidepressants; estrogens), thyroid dysfunction (hypothyroidism), pituitary disorders (most notably prolactin-secreting adenomas), chest wall irritation or injury, renal or hepatic disease, and less commonly systemic illness. Endocrine and neurologic symptoms such as irregular menses, galactorrhea with infertility, headaches, or visual changes may accompany hyperprolactinemia.

Evaluation starts with a careful history and physical examination, including pregnancy testing and breast exam. Laboratory assessment typically includes serum prolactin and thyroid-stimulating hormone with free thyroxine; pregnancy testing is essential. If prolactin is elevated or no clear cause is identified, magnetic resonance imaging of the pituitary is often recommended to evaluate for a prolactinoma. Additional tests may be guided by symptoms and initial results.

Management focuses on treating the underlying cause. Offending medications can be adjusted or discontinued when feasible. Hypothyroidism is treated to lower prolactin levels. For persistent hyperprolactinemia, dopamine agonists such as cabergoline or bromocriptine are commonly used; they reduce prolactin levels and may shrink prolactin-secreting tumors. In pregnant individuals, management is individualized, as galactorrhea can be physiologic in late pregnancy. Referral to endocrinology or neurosurgery is considered for resistant cases or when visual symptoms occur.

Prognosis varies with the cause; functional or physiological galactorrhea often resolves, whereas untreated hyperprolactinemia can affect fertility and bone health.