The need to empty the breasts when the mother is not distended is determined by a number of factors, including the amount of milk produced by the mother, her physical condition and the needs of the baby. I. Need to empty: 1. Insufficient milk: If a lactating mother does not have enough milk, she still needs to empty her breasts regularly even if she is not distended, and it is recommended to suck milk once in about 3 hours. Sucking can prompt the lactating cells to produce the spray reflex, so that more milk enters the breast sinus, thus promoting milk secretion; 2. High tolerance for distention: different mothers have different tolerance for distention, some mothers have higher tolerance for the pain caused by distention, although there is milk stagnation, but the mothers do not feel it obviously, at this time the excess milk can accumulate in the breast and block the milk ducts, which can cause bacterial infection leading to mastitis in serious cases. The mother and the baby are separated: if for some reason the mother and the baby are separated, the breast should be emptied regularly even if it is not distended, so as to stimulate the brain to release prolactin and make the breast empty regularly, so as not to affect breastfeeding. 2. No need to empty: If the milk secreted by the mother and the baby sucking are in a balance of supply and demand, you can continue to breastfeed on demand and there is no need to empty the breast in the absence of breast distention.