I'm female, 26, not pregnant, not sexually active, don't have kids. A couple days ago I noticed my nipples feeling tender and sore, but I didn't bother checking since it happens often before my period. However yesterday I noticed that my right nipple has become brown in color, when both have always been a slightly dark pink. around the brown nipple there is some redness on the areola. The brown part feels very dry/rough, but its different from normal slightly dry feeling of my left nipple (which remained unchanged). It also is lacking in sensitivity at the brown part, like the feeling that you're touching a scab rather than actual skin. There is no discharge or irregular bumps. There's no pain, and both nipples are not sore anymore after I noticed the change in the right one. The rest of my areola that's not slightly red is completely normal. I have not changed my lifestyle at all in the past half a year or so.