Nipple pain when touched can happen for several reasons, including friction or chafing from clothing, hormonal changes, skin conditions (like eczema or dermatitis), infections, or irritation from nipple stimulation. Tight or poorly fitting clothes rubbing against the nipple can cause soreness. Hormonal fluctuations around menstruation, pregnancy, or breastfeeding can make nipples tender. Skin conditions and allergies may cause itching, redness, and soreness around the nipple. Infections, though less common, can also lead to nipple pain and require medical attention. Rarely, nipple pain can be a sign of more serious conditions such as Paget's disease or breast cancer, especially if accompanied by unusual nipple changes or discharge.

If the nipple pain is persistent, severe, or accompanied by other symptoms such as discharge, lumps, changes in nipple appearance, or signs of infection (redness, swelling, fever), it is important to see a healthcare professional for evaluation.