During breastfeeding, some people feel that their nipples hurt when the baby is wrapped in milk, or even when the nipples are not wrapped in milk, which is normal. This is because the nipple contains the ducts of the breast, which are distributed in a dendritic pattern downward throughout the breast, and the breast contains the glandular vesicles of the breast. There are smooth muscle cells in the walls of the ducts and vesicles. When there is a lactation reflex, such as when a child sucks milk, the smooth muscle of the glandular ducts and alveoli of the other breast will contract, and sometimes the other breast will flow or overflow with milk, and there will be a tingling sensation, which is normal. Therefore, tingling in the breast and nipple during breastfeeding is normal. It is important to take care of your nipples during breastfeeding and to express the excess milk in time. If there is inflammation of the nipple and breast, milk accumulates inside and becomes inflamed, or the nipple is wrapped and inflamed by the child, then there is also tingling in the nipple and pain in the breast, which should be treated, and if necessary, you can also go to the hospital to seek help from a doctor.