The let-down reflex (also called just \”let-down\” or the milk ejection reflex) happens when your baby begins to nurse. The nerves in your breast send signals that release the milk into your milk ducts. Let-down happens a few seconds to several minutes after you start breastfeeding your baby. It also can happen a few times during a feeding. You may feel a tingle in your breast or you may feel a little uncomfortable. You also may not feel anything.
Let-down can happen at other times, too, such as when you hear your baby cry or when you\’re just thinking about your baby. If your milk lets down as more of a gush and it bothers your baby, try expressing some milk by hand before you start breastfeeding.
Many factors affect let-down, including anxiety, pain, embarrassment, stress, cold, excessive caffeine use, smoking, alcohol, and some medicines. Mothers who have had breast surgery may have nerve damage that interferes with let-down.