The causes of nipple pinching pain are nipple injury, cystic hyperplasia of the breast, acute mastitis, as follows: 1, nipple injury: excessive force when pinching the nipple, causing local injury to the nipple, acute inflammatory changes, manifested as redness and swelling of the nipple accompanied by painful discomfort; 3, cystic hyperplasia of the breast: when the nipple is pinched by hand causes an increase in the level of estrogen in the body, inducing an acute attack of cystic hyperplasia of the breast, manifested as The pain and swelling of the breast increases, and can spread to the nipple, the phenomenon of nipple pain; 3, acute mastitis: mostly occurs in lactating women, as an acute purulent infection of the breast, clinical manifestations of the breast redness, swelling, heat, pain, and can appear to have pus overflow from the nipple. If you can exclude nipple pain caused by nipple injury, you should promptly perform breast ultrasound examination to clarify the breast lesion and carry out reasonable treatment under the guidance of a specialist.