Final answer:
Breast engorgement and leakage after abruptly stopping breastfeeding occurs due to the continued production of milk in response to hormonal signals established during breastfeeding, which does not immediately stop after ceasing suckling.
Step-by-step explanation:
A person who stopped breastfeeding suddenly is experiencing breast engorgement and leakage because of the abrupt change in the pattern of milk removal. Breast engorgement is a result of milk accumulating in the breasts, which occurs when the established balance between milk supply and infant demand is disrupted. When breastfeeding is stopped, the milk that was being produced in response to the baby's need continues to be produced until the body gradually adjusts to the reduced demand. This process can lead to temporary engorgement and leakage.
The lactation process is regulated by hormones such as prolactin and oxytocin. Frequent breastfeeding maintains high levels of prolactin, which stimulates milk production. The action of the baby suckling also prompts oxytocin release, leading to milk ejection. When suckling is ceased suddenly, these hormonal signals do not drop immediately; hence the body continues to produce milk even without the baby's demand, causing engorgement and leakage.