Nipple and/or breast pain can be a breastfeeding deal-breaker. If breastfeeding is not supposed to hurt, then why do so many mothers experience pain while breastfeeding? Is it maternal anatomy, faulty physiology, infant sucking alterations or anamolies? This presentation will look at nipple anatomy, the changes nipples experience during pregnancy, precursors and causes of nipple pain, and the magic number of 7 millimeters. Can 7mm serve as a screening tool for potential breastfeeding problems? If nipple pain is bad, then what about breast pain? An exploration of breast pain looks at the contributors to an unwelcome lactation guest.