The nipple is soft is usually caused by physiological factors or acute mastitis, it is recommended to find out the cause of the disease, under the guidance of the doctor to choose the appropriate treatment. 1. Physiological: After the menstrual period or breastfeeding period because of hormonal changes nipples will feel soft, this is a normal physiological phenomenon, do not need to pay too much attention to, usually have to maintain a good lifestyle. 2. Acute mastitis: If the breastfeeding acute mastitis purulent infection may appear breast tissue edema, will feel nipple soft. Acute mastitis occurs in newborns who are breastfeeding after giving birth, and the onset of the disease occurs three to four weeks after giving birth. The breasts are swollen and painful at first, then hard lumps may appear, chills and high fever may occur, and breast abscesses may appear. If nipple tenderness occurs and is accompanied by other uncomfortable symptoms, it is recommended to seek prompt medical attention and choose the appropriate treatment under the guidance of the doctor.