White spots on the breast during breastfeeding may be caused by the following: First, it may be due to ulcers on the breast after the nipple has cracked for some reason, mostly because the child does not suck the entire nipple completely into the mouth while breastfeeding and keeps sucking repeatedly resulting in breakage and the formation of white ulcer spots. Secondly, it may be due to the accumulation of milk inside the breast to form a pile, clotting, and after a long period of time without treatment the milk becomes dehydrated and forms a white dot-like substance. Finally, there may be white skin formed after being sucked by the child for a long time, or it may be due to dehydration from dryness, as well as inflammation from bacterial infection of the breast. It is best to go to the hospital mammography department and choose the appropriate treatment according to the cause, considering that breastfeeding is more critical, never use medication on your own.