Jun 13, - Wherever you find yourself on the spectrum, we believe these curious nipple facts will thrill you. Your nipples are perfect. No two nipples are. Dec 8, - Sometimes, it's more than just imbalanced hormones causing sore nipples. Mastitis is a condition where tissue in the breast and nipples become inflamed. The nipples become red, swollen and painful to touch. Mastitis most commonly occurs during breastfeeding.