Final answer:
Bloody nipple discharge without breast masses or skin changes is most commonly caused by intraductal papilloma, a benign tumor in the breast ducts. However, medical consultation is essential, as it is also a potential sign of more serious conditions like breast cancer.
Step-by-step explanation:
The most common cause of bloody nipple discharge, typically presenting without breast masses or skin changes, is intraductal papilloma. Intraductal papillomas are benign (non-cancerous) tumors that form in the milk ducts of the breast. Although concerning, this type of nipple discharge often occurs without the presence of other alarming symptoms such as a lump in the breast or obvious skin changes. It is essential for anyone experiencing bloody nipple discharge to consult with a healthcare provider to rule out other causes, which could include breast cancer or other benign breast conditions. Besides bloody nipple discharge, other warning signs that warrant a medical consultation include unusual bleeding or discharge from any body part, thickening or lump in the breast or elsewhere, chronic indigestion or difficulty swallowing, obvious changes in a wart or mole, and persistent coughing or hoarseness.