Final answer:
Breast engorgement after abrupt cessation of breastfeeding is caused by accumulated milk in the mammary glands due to the continued production of milk prompted by hormonal levels, particularly prolactin.
Step-by-step explanation:
The sensation of breast engorgement that a woman experiences when she stops breastfeeding suddenly is due to the accumulation of milk in the mammary glands. When a mother breastfeeds, prolactin is released, stimulating the mammary glands to produce milk, while the hormone oxytocin promotes the release of milk. Ceasing breastfeeding abruptly can lead to the mammary glands continuing to produce milk due to the existing levels of prolactin, but without the regular removal of milk by the baby, this leads to engorgement. Engorgement is typically caused by a combination of factors including hormonal changes, excessive milk production, and potential blocked milk ducts.