If your nipple skin is delicate and your baby enjoys marathon nursing sessions, you may end up with this painful problem. Buy a tube of pure lanolin ointment most stores that sell breastfeeding supplies carry it and keep a thin coating of ointment on your nipples whenever your baby isn't nursing. The good thing about lanolin is that it will not harm your baby, so you don't need to wipe it off to nurse. Its texture actually can help the baby latch on properly.
To prevent cracked nipples, air them out frequently. If you would rather not go braless, turn the flaps of your nursing bra down for a while each day. Do not use plastic-lined breast shields; stick with washable cotton or disposables without plastic linings. Also try Phytolacca decandra, a homeopathic remedy, for cracked nipples. This remedy can also work well for mastitis.