Galactorrhoea

Galactorrhoea is inappropriate - i.e. non-puerperal - lactation:

• is milk production from the breast unrelated to pregnancy or lactation
• is a clinical sign rather than a disease entity and can be physiological, pathological, or pharmacological
• is reported to occur in around 20-25% of all women at some point in their lives (1)
• milk production one year after cessation of breastfeeding is non-lactational and is considered galactorrhoea (2)

In premenopausal women, without amenorrhoea, who have normal prolactin, around 30% of galactorrhoea cases are idiopathic; in men and postmenopausal women, galactorrhoea usually indicates underlying pathology (1).

Hyperprolactinaemia is the most common cause of galactorrhoea, with up to 80% of women with non-puerperal hyperprolactinaemia experiencing galactorrhoea (1).

Medications may cause hyperprolactinaemia and consequently galactorrhoea and include (1,2):

• atypical antipsychotics
  • antipsychotic medications especially associated with risperidone, amisulpride, and first generation antipsychotics such as haloperidol
• metoclopramide and domperidone
• tricyclic antidepressants (especially clomipramine)
• opioids
• verapamil

If galactorrhoea then measure serum prolactin in all premenopausal women with a negative pregnancy test, and all men and postmenopausal women (1):

• check thyroid, renal, and liver function for all individuals with confirmed hyperprolactinaemia
  • recognised causes of hyperprolactinaemia include primary hypothyroidism, renal insufficiency, and liver failure
    • note though that the extent to which hyperprolactinaemia secondary to renal insufficiency and liver failure is likely to cause galactorrhoea is less well defined
  • magnetic resonance imaging (MRI) of the pituitary gland may reveal lesions of the pituitary gland responsible for hyperprolactinemia (2)
    • visual field assessment needs to be performed when the tumour is in contact with the optic chiasma on MRI

Specialist referral is suggested if (1):

• unexplained hyperprolactinaemia after excluding pregnancy, medication induced causes, and primary hypothyroidism
• hypogonadism/menstrual disturbance
• male or postmenopausal galactorrhoea
• if there is headache, visual field defects, or other neurological symptoms
• suspected medication induced hyperprolactinemia, where the causative drug cannot be stopped, or when the onset of galactorrhoea does not align with treatment initiation
• troublesome galactorrhoea with normal prolactin levels, when a trial of dopamine receptor agonist therapy is being considered
• difficulty interpreting prolactin results (eg, possible stress induced elevations, macroprolactin)

Management principles:

• depends on cause
• mainstay of hyperprolactinaemia is treatment with bromocriptine or cabergoline
• if medication-induced hyperprolactinemia, then the offending medication should be stopped or changed to a different class (1,2)
  • for medication induced hyperprolactinaemia causing galactorrhoea, the Endocrine Society recommends a trial of discontinuing the suspected medication for three days or switching to an alternative agent, followed by repeat measurement of serum prolactin levels
  • use of dopamine agonists in these instances has associations with a slight risk of exacerbating the psychiatric disorder (2)

Reference:

1. Mills E G, Parekh R, de Silva N L, Miller K, Martin N M. Assessment and management of galactorrhoea. BMJ 2026; 392 :e086122.
2. Gosi SKY, Garla VV. Galactorrhea. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-.