What is a let-down?
Let-down is the process that leads to the delivery of milk to the baby. Milk is made and then stored in tiny milk sacs until the baby is hungry. When the baby starts to breastfeed, the body sends a signal to a gland (the pituitary) at the base of the brain. The gland releases a hormone (oxytocin) that causes muscles around the milk sacs to squeeze, sending milk into the ducts of the breast and towards the nipple. Let-downs happen several times during each breastfeeding but can also happen simply when the breasts are full. They can be painful, or they may not be felt at all.