What does it mean when you have hard and sore nipples but have no babies?

Hard and sore nipples without having had a baby could indicate hormonal changes in your body, such as those caused by menstruation, pregnancy, or hormonal imbalances. Conditions like fibrocystic breast changes or mastitis can also lead to nipple discomfort. If the soreness persists or is accompanied by other symptoms, it may be advisable to consult a healthcare professional for further evaluation.