Final answer:
Galactorrhea can be caused by excessive production of prolactin, hormonal changes during pregnancy and breastfeeding, certain medications, and medical conditions.
Step-by-step explanation:
Galactorrhea refers to the unnecessary discharge of milk from the breast, which can occur in individuals who are not pregnant or breastfeeding. This condition is often associated with the excessive production of prolactin, a hormone responsible for milk production. There are various causes of galactorrhea, including problems with the hypothalamus or pituitary gland, where prolactin is produced, side effects from certain medications, thyroid dysfunction, and other health issues. During lactation, hormones such as prolactin, oxytocin, growth hormone, cortisol, parathyroid hormone, and insulin contribute to the process, and any imbalances or disruptions to these hormones can result in galactorrhea. Additionally, physical changes or stimulation to the breast, as well as stress or clothing that irritates the breasts, can lead to excess milk production.